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| answers
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|---|---|---|---|---|---|---|
Cuaderno_2013_1_Q | 2013 | chemistry | 12 | The standard equilibrium constant for a reaction between ideal gases: | 4 | [
{
"aid": 1,
"atext": "It depends on the initial quantities of the reagents."
},
{
"aid": 2,
"atext": "It takes different values if the reaction is carried out at different pressures."
},
{
"aid": 3,
"atext": "It depends on the volume of the vessel in which the reaction is carried out."
},
{
"aid": 4,
"atext": "It only depends on the temperature."
},
{
"aid": 5,
"atext": "It depends on the nature of the gases."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 13 | The antitumor agent cis-platinum: | 1 | [
{
"aid": 1,
"atext": "It is a flat square complex of Pt (II) with 2 molecules of ammonia and 2 chloride anions located in cis."
},
{
"aid": 2,
"atext": "It is a flat square complex of Pt (IV) with 2 molecules of ammonia and 2 chloride anions located in cis."
},
{
"aid": 3,
"atext": "It is an octahedral complex of Pt (IV) with 2 molecules of ammonia in cis and 4 chloride anions in the other positions."
},
{
"aid": 4,
"atext": "It is an octahedral complex of Pt (II) with 2 chloride anions in cis and 4 ammonia molecules in the other positions."
},
{
"aid": 5,
"atext": "It is an alkene with two Pt atoms in the two cis positions with respect to the double bond."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 14 | Sodium metal reacts violently with water because Na: | 2 | [
{
"aid": 1,
"atext": "Oxidize the water to oxygen, and the reaction is very exothermic."
},
{
"aid": 2,
"atext": "It reduces the water to hydrogen, and the reaction is very exothermic."
},
{
"aid": 3,
"atext": "Oxidizes the water to oxygen, and when a gas is generated, the entropy increases enormously."
},
{
"aid": 4,
"atext": "It reduces the water to hydrogen, and the reaction is very endothermic."
},
{
"aid": 5,
"atext": "It combines with water giving rise to an explosive hydride."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 15 | The number of molecules per unit cell is a structure centered on all faces is: | 4 | [
{
"aid": 1,
"atext": "A."
},
{
"aid": 2,
"atext": "Two."
},
{
"aid": 3,
"atext": "Three."
},
{
"aid": 4,
"atext": "Four."
},
{
"aid": 5,
"atext": "Six."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 16 | Regal water dissolves gold because of its two components: | 3 | [
{
"aid": 1,
"atext": "Sulfuric acid acts as an oxidant and hydrochloric acid forms a soluble chlorinated complex of Au3 +."
},
{
"aid": 2,
"atext": "Hydrochloric acid increases the oxidizing power of nitric acid."
},
{
"aid": 3,
"atext": "Nitric acid acts as an oxidant and hydrochloric acid forms a soluble chlorine complex of Au3 +."
},
{
"aid": 4,
"atext": "Hydrochloric acid acts as an oxidant and nitric acid forms a soluble complex of Au3 +."
},
{
"aid": 5,
"atext": "Nitric acid acts as an oxidant and hydrochloric acid forms a soluble chlorinated complex of Au2 +."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 17 | A light-emitting diode: | 2 | [
{
"aid": 1,
"atext": "It is the same as a photovoltaic cell."
},
{
"aid": 2,
"atext": "It is the inverse of a photovoltaic cell."
},
{
"aid": 3,
"atext": "It is the same as a photovoltaic cell."
},
{
"aid": 4,
"atext": "It is the inverse of a photovoltaic cell."
},
{
"aid": 5,
"atext": "It is equivalent to a photochemical cell."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 18 | In the most general case, the wave function of a quantum mechanical system: | 2 | [
{
"aid": 1,
"atext": "It is defined for each electron and only depends on the coordinates of that electron."
},
{
"aid": 2,
"atext": "It depends on the spatial coordinates of all the particles that make up the system and time."
},
{
"aid": 3,
"atext": "It never depends on time."
},
{
"aid": 4,
"atext": "It is found as a solution to the equations of motion proposed by Newton."
},
{
"aid": 5,
"atext": "It can always be decomposed into sum of equations for each of the particles that make up the system."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 19 | The equation of speed of a chemical reaction: | 1 | [
{
"aid": 1,
"atext": "It must be determined from kinetic measurements and can not be deduced directly from the stoichiometry of the reaction."
},
{
"aid": 2,
"atext": "Allows the units of s-1 (s = second) to be assigned to the velocity constant."
},
{
"aid": 3,
"atext": "It depends on the total reaction order that, in turn, is obtained from the stoichiometric coefficients of the products."
},
{
"aid": 4,
"atext": "Report in detail about the reaction mechanism."
},
{
"aid": 5,
"atext": "It depends on the experimental conditions of the process."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 20 | The nitrogen: | 4 | [
{
"aid": 1,
"atext": "It is a highly reactive gas at room temperature."
},
{
"aid": 2,
"atext": "Nitrogen molecules are constituted by two atoms linked together by a single bond."
},
{
"aid": 3,
"atext": "It has a higher reactivity than other isoelectronic molecules such as CO, CNo or NO +."
},
{
"aid": 4,
"atext": "At a sufficient temperature, it reacts with H2 to give NH3."
},
{
"aid": 5,
"atext": "It barely forms binary compounds with the rest of the elements of the Periodic Table."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 21 | The number 0.0670 has: | 3 | [
{
"aid": 1,
"atext": "5 significant figures."
},
{
"aid": 2,
"atext": "4 significant figures."
},
{
"aid": 3,
"atext": "3 significant figures."
},
{
"aid": 4,
"atext": "2 significant figures."
},
{
"aid": 5,
"atext": "1 significant figure."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 22 | The Pearson correlation coefficient: | 5 | [
{
"aid": 1,
"atext": "It is always greater than 1."
},
{
"aid": 2,
"atext": "It is always less than 1."
},
{
"aid": 3,
"atext": "It is between 0 and 1."
},
{
"aid": 4,
"atext": "It is between -1 and 0."
},
{
"aid": 5,
"atext": "It is between -1 and 1."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 23 | Separations by capillary zone electropheresis (CZE) are characterized in that the electrophoretic medium: | 3 | [
{
"aid": 1,
"atext": "It is always formed by 1.0 M HCl."
},
{
"aid": 2,
"atext": "It is always formed by NH3 1.0 M."
},
{
"aid": 3,
"atext": "It is homogeneous throughout the capillary."
},
{
"aid": 4,
"atext": "It is not homogeneous throughout the capillary."
},
{
"aid": 5,
"atext": "It has a pH gradient throughout the entire capillary."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 24 | Linear scanning polarography uses a working electrode of: | 1 | [
{
"aid": 1,
"atext": "Drops of mercury"
},
{
"aid": 2,
"atext": "Iodine drops"
},
{
"aid": 3,
"atext": "Platinum."
},
{
"aid": 4,
"atext": "Calomelanos"
},
{
"aid": 5,
"atext": "Drops of cerium nitrate."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 25 | Iodine is poorly soluble in water ( 0.001M). Therefore, to obtain useful solutions as an analytical reagent it is dissolved in: | 4 | [
{
"aid": 1,
"atext": "0.1 M potassium nitrate"
},
{
"aid": 2,
"atext": "Perchloric acid 0.01 M."
},
{
"aid": 3,
"atext": "Excess of calcium nitrate."
},
{
"aid": 4,
"atext": "Potassium iodide."
},
{
"aid": 5,
"atext": "Hot water."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 26 | The determination of cyanide by the Liebig method is based on the addition of a silver nitrate standard solution: | 2 | [
{
"aid": 1,
"atext": "Until complete precipitation of silver cyanide."
},
{
"aid": 2,
"atext": "Until the precipitation of silver cyanide begins."
},
{
"aid": 3,
"atext": "Until the appearance of a red precipitate of silver chromate."
},
{
"aid": 4,
"atext": "Until the AgCN complex is quantitatively formed."
},
{
"aid": 5,
"atext": "Until the precipitation of silver iodide, yellow."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 27 | When the electromagnetic radiation passes from the air to a medium like glass its wavelength: | 5 | [
{
"aid": 1,
"atext": "It remains unchanged."
},
{
"aid": 2,
"atext": "Increase approximately 10 nm."
},
{
"aid": 3,
"atext": "Increase approximately 100 nm."
},
{
"aid": 4,
"atext": "It decreases approximately 1 nm."
},
{
"aid": 5,
"atext": "It decreases approximately 200 nm."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 28 | In an evaluation the redox indicator In (ox) + ne- In (network) is used, whose normal potential is E0. The color change will occur: | 3 | [
{
"aid": 1,
"atext": "To the potential of the equivalence point."
},
{
"aid": 2,
"atext": "To the value of E0."
},
{
"aid": 3,
"atext": "In the interval E0 0.059 / n."
},
{
"aid": 4,
"atext": "In the interval E0 (ox) - E0 (network) if it is evaluated with a reducer."
},
{
"aid": 5,
"atext": "At the potential of 0.059 / n."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 30 | When an experimental design is carried out, it is fundamentally sought: | 3 | [
{
"aid": 1,
"atext": "Know better the average of the results obtained and repeated in an experiment."
},
{
"aid": 2,
"atext": "Know better the median of the results obtained in an experiment."
},
{
"aid": 3,
"atext": "Identify better the factors that can affect the experiment."
},
{
"aid": 4,
"atext": "To better identify the regression equations in an experiment."
},
{
"aid": 5,
"atext": "To know better the standard deviation of the different data in the experiment."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 31 | The gas used to generate the ICP plasma (coupled induction plasma) is: | 3 | [
{
"aid": 1,
"atext": "Hydrogen for being diatomic, chemically inert and with a low ionization energy."
},
{
"aid": 2,
"atext": "Oxygen because it is diatomic, highly reactive and with a high ionization energy."
},
{
"aid": 3,
"atext": "Argon, being monatomic, chemically inert and with a high ionization energy."
},
{
"aid": 4,
"atext": "Xenon, being monatomic, highly reactive and with a low ionization energy."
},
{
"aid": 5,
"atext": "None of the above is correct, because the gas used is helium."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 32 | In the titration curve of a diprotic acid, the three points whose pH only depends on the dissociation constants are: | 2 | [
{
"aid": 1,
"atext": "The starting point and the equivalence points."
},
{
"aid": 2,
"atext": "The first point of equivalence and the two points of semi-neutralization."
},
{
"aid": 3,
"atext": "The first semi-neutralization point and the two equivalence points."
},
{
"aid": 4,
"atext": "The starting point, the first semi-neutralization point and the first equivalence point."
},
{
"aid": 5,
"atext": "The starting point and the two semi-neutralization points."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 33 | The validation of an analytical method includes: | 1 | [
{
"aid": 1,
"atext": "Validate the analytical process as a whole, validate the range of concentrations in which it is applied and validate the method in each of the matrices to which it will be applied."
},
{
"aid": 2,
"atext": "It only includes validating the range of concentrations in which it is applied."
},
{
"aid": 3,
"atext": "It only includes validating the method in each of the matrices to which it will be applied."
},
{
"aid": 4,
"atext": "It is only necessary to validate the treatment stages of the samples prior to the analytical measurement."
},
{
"aid": 5,
"atext": "It is only necessary to validate the instrumentation by means of suitable calibrations."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 34 | In an electrochemical cell, the supporting electrolyte serves to: | 4 | [
{
"aid": 1,
"atext": "That the principle of electroneutrality in the dissolution is fulfilled."
},
{
"aid": 2,
"atext": "That their ions are electrolized preferably in order to prevent the consumption of electroactive substance."
},
{
"aid": 3,
"atext": "That in the cell there is transport by migration, in order to achieve greater sensitivity."
},
{
"aid": 4,
"atext": "That the solution has an adequate electrical conductivity."
},
{
"aid": 5,
"atext": "Encourage transport by diffusion of the electroactive substance."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 35 | The traceability of an analytical method can be demonstrated: | 2 | [
{
"aid": 1,
"atext": "Carrying out the study of its selectivity."
},
{
"aid": 2,
"atext": "By comparison with a reference method, use of certified reference materials and / or analysis of added samples."
},
{
"aid": 3,
"atext": "Checking that the limit of detection of it is very low."
},
{
"aid": 4,
"atext": "Evaluating the linearity of the calibration, whose most appropriate criterion is the correlation coefficient."
},
{
"aid": 5,
"atext": "Making replicated measurements of the patterns and carrying out the analysis of the variance."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 36 | A selective calcium electrode is characterized by having: | 5 | [
{
"aid": 1,
"atext": "A membrane that is a solid crystal."
},
{
"aid": 2,
"atext": "An internal solution of 0.1 M HCl"
},
{
"aid": 3,
"atext": "An internal silver electrode."
},
{
"aid": 4,
"atext": "A membrane of silver salts."
},
{
"aid": 5,
"atext": "An internal aqueous solution of CaCl 2 saturated with AgCl."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 37 | Potentiometric titration of chloride with a silver electrode, using a silver ion standard solution: | 3 | [
{
"aid": 1,
"atext": "It is based on the formation of silver complexes in the presence of a high concentration of chloride."
},
{
"aid": 2,
"atext": "Follow the Nernst equation, in which the variation of the potential varies linearly with the concentration of silver ion."
},
{
"aid": 3,
"atext": "It shows an equivalence point where pAg does not depend on the chloride concentration."
},
{
"aid": 4,
"atext": "It gives rise to potential variations that depend on the amount of AgCl formed."
},
{
"aid": 5,
"atext": "It provides a titration curve in which the jump of pAg does not depend on the concentration of chloride."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 38 | The alkaline error is defined as: | 2 | [
{
"aid": 1,
"atext": "Error that is committed when a strong base is valued."
},
{
"aid": 2,
"atext": "Error that presents a glass electrode when the medium is very basic."
},
{
"aid": 3,
"atext": "Error that is committed when a strong acid is valued."
},
{
"aid": 4,
"atext": "Error affecting a reference electrode."
},
{
"aid": 5,
"atext": "Own error of liquid membrane electrodes."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 39 | The loss of linearity of the calibration line when the fluorescence intensity is used as an analytical parameter may be due to: | 5 | [
{
"aid": 1,
"atext": "Changes in solvent density as the concentration of fluorescent analyte increases."
},
{
"aid": 2,
"atext": "Dissolved oxygen, due to its diamagnetic character, which favors intersystem crossing."
},
{
"aid": 3,
"atext": "The presence of static inhibitors of the incident radiation."
},
{
"aid": 4,
"atext": "Internal conversion, in which the energy absorbed can be transformed into heat energy."
},
{
"aid": 5,
"atext": "Self-absorption, to the internal effect of bucket and to the formation of dimers and excimers."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 40 | A columbimétrica valuation: | 4 | [
{
"aid": 1,
"atext": "It is always done at controlled potential."
},
{
"aid": 2,
"atext": "Always use a platinum macroelectrode."
},
{
"aid": 3,
"atext": "It does not need a system indicating the end point."
},
{
"aid": 4,
"atext": "You need the current to be controlled."
},
{
"aid": 5,
"atext": "You always need the titrant to be added from a burette."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 41 | Liquid chromatography using linked stationary phases can be divided into normal phase and reverse phase phases. In this context it can be said that: | 1 | [
{
"aid": 1,
"atext": "The main separation mechanism in reverse phase is the distribution, while adsorption also plays a very important role in the normal phase."
},
{
"aid": 2,
"atext": "In normal phase chromatography, a large number of non-polar stationary phases can be used."
},
{
"aid": 3,
"atext": "The main separation mechanism in normal phase is the distribution, while the adsorption plays a very important role in the reverse phase."
},
{
"aid": 4,
"atext": "In reverse phase chromatography, the stationary phase is polar and the non-polar eluents."
},
{
"aid": 5,
"atext": "In reverse phase chromatography, a large number of polar stationary phases can be used."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 42 | Many of the properties of liquid chromatography (HPLC) and capillary electrophoresis (CE) have to do with its flow profile. In this way, the flow profile is: | 5 | [
{
"aid": 1,
"atext": "Laminate in HPLC and turbulent in CE."
},
{
"aid": 2,
"atext": "Straight in CE and turbulent in HPLC."
},
{
"aid": 3,
"atext": "Hyperbolic in EC and parabolic in HPLC."
},
{
"aid": 4,
"atext": "Laminar in CE and electroosmotic in HPLC."
},
{
"aid": 5,
"atext": "Parabolic in HPLC and flat in CE."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 43 | The corrector Zeeman: | 2 | [
{
"aid": 1,
"atext": "It is widely used in Molecular Fluorescence to correct the internal filter effect."
},
{
"aid": 2,
"atext": "It is a basic corrector in atomic absorption spectrometry, which is based on the property that atoms have in the form of atomic vapor of unfolding their electronic energy levels when subjected to an intense magnetic field, originating different emission lines for each transition electronics."
},
{
"aid": 3,
"atext": "It is based on the phenomenon of self-absorption that occurs when the hollow cathode lamp is subjected to high currents and is widely used in atomic absorption spectrometry."
},
{
"aid": 4,
"atext": "It is based on the emission of continuous radiation in the ultraviolet region of a deuterium lamp, used as a background corrector."
},
{
"aid": 5,
"atext": "It is a corrector of chemical interferences, widely used in atomic emission spectrometry."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 44 | When we inject 1 nanoliter (nL) sample we are referring to the injection of: | 4 | [
{
"aid": 1,
"atext": "10-1 L."
},
{
"aid": 2,
"atext": "10-3 L."
},
{
"aid": 3,
"atext": "10-6 L."
},
{
"aid": 4,
"atext": "10-9 L."
},
{
"aid": 5,
"atext": "10-12 L."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 45 | For the determination of polychlorinated biphenyls is an environmental sample by gas chromatography, the most appropriate detector would be: | 2 | [
{
"aid": 1,
"atext": "Of flame ionization."
},
{
"aid": 2,
"atext": "Of electronic capture."
},
{
"aid": 3,
"atext": "Thermoionic"
},
{
"aid": 4,
"atext": "Of photoionization."
},
{
"aid": 5,
"atext": "Amperometric."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 46 | Gas chromatography combined with mass spectrometry (GC-MS) is the most commonly used chromatographic coupled technique. The main difficulty of the coupling is in: | 5 | [
{
"aid": 1,
"atext": "The analysis of molecular ions in the same place where they are generated."
},
{
"aid": 2,
"atext": "The production of highly fragmented ions with accelerated electron generation."
},
{
"aid": 3,
"atext": "The increase in the output flow rate of the chromatograph, which can not exceed nL / min."
},
{
"aid": 4,
"atext": "The obtaining of the bidimensional spectrum that allows the separation in function of the relationship q / r."
},
{
"aid": 5,
"atext": "The introduction into the high vacuum of the mass analyzer, of a compound that is at an atomospheric pressure."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 47 | For the analysis of traces of inorganic constituents, in samples of organic nature, a preliminary treatment of the sample is needed, which normally consists of: | 4 | [
{
"aid": 1,
"atext": "Dissolve the sample in cold water."
},
{
"aid": 2,
"atext": "Dissolve the sample in hot water."
},
{
"aid": 3,
"atext": "Dissolve the sample between 30 and 70 ºC."
},
{
"aid": 4,
"atext": "Heat the sample between 400 and 700 ºC."
},
{
"aid": 5,
"atext": "Heat the sample in 0.1 M hydrochloric acid."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 48 | Linear sweep voltammetry is characterized by: | 2 | [
{
"aid": 1,
"atext": "To be a technique based on a stationary diffusion regime."
},
{
"aid": 2,
"atext": "To be a voltammetric technique based on a pure diffusion regime."
},
{
"aid": 3,
"atext": "Use a rotating electrode as working electrode."
},
{
"aid": 4,
"atext": "Use a hanging drop electrode as the working electrode."
},
{
"aid": 5,
"atext": "Have an electrode preconcentration stage."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 49 | In suppression ion chromatography: | 2 | [
{
"aid": 1,
"atext": "A single column is used and the conductivity of the mobile phase is kept very low."
},
{
"aid": 2,
"atext": "The eluent must be able to be removed selectively after separation and prior to the conductometric measurement."
},
{
"aid": 3,
"atext": "The eluent incorporates a regenerating solution of strong acid flowing in the same direction as the mobile phase."
},
{
"aid": 4,
"atext": "Weak exchangers are used from polystyrene polymers."
},
{
"aid": 5,
"atext": "A mobile phase with ionic conductivity gradient is used."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 50 | Voltammetry of anodic redissolution: | 5 | [
{
"aid": 1,
"atext": "It is always carried out with mercury film electrodes."
},
{
"aid": 2,
"atext": "It uses an oxidation process with chemical agents."
},
{
"aid": 3,
"atext": "It is based on the formation of mercury salts in the electrode."
},
{
"aid": 4,
"atext": "It does not need background electrolyte."
},
{
"aid": 5,
"atext": "It has an electrodeposition stage."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 51 | The near infrared is the area of the electromagnetic spectrum comprised between: | 4 | [
{
"aid": 1,
"atext": "100-250 nm."
},
{
"aid": 2,
"atext": "200-450 nm."
},
{
"aid": 3,
"atext": "600-750 nm."
},
{
"aid": 4,
"atext": "800-2500 nm."
},
{
"aid": 5,
"atext": "3000-8000 nm."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 52 | The voltammetric methods of anodic redissolution: | 4 | [
{
"aid": 1,
"atext": "They are based on the preconcentration of analytes on the surface of an electrode and are characterized by their low sensitivity, since the surface of the electrode is very small."
},
{
"aid": 2,
"atext": "They apply exclusively to the determination of traces of metals by oxidation on a mercury electrode."
},
{
"aid": 3,
"atext": "They require the application of a stage of accumulation and another of redisolution in which intensity-time curves are recorded."
},
{
"aid": 4,
"atext": "They are used for the determination of metals that, once deposited, are oxidized electrochemically."
},
{
"aid": 5,
"atext": "They are based on the variation of the potential that the working electrode experiences as the deposited substance is redissolved."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 53 | The thermal conductivity detector was one of the first used in gas chromatography and still has a lot of application. Consists in: | 1 | [
{
"aid": 1,
"atext": "A source that is heated by electricity, whose temperature at a constant electrical energy depends on the thermal conductivity of the gas that surrounds it."
},
{
"aid": 2,
"atext": "A metallic surface on which ions collide, producing emission of electrons or other ions, with the consequent variation in conductivity."
},
{
"aid": 3,
"atext": "An air / hydrogen flame where organic compounds are pyrolyzed producing ions that lead to a change in conductivity."
},
{
"aid": 4,
"atext": "An emitter of beta radiation that allows the measurement of the conductivity of the eluent that leaves the chromatographic column."
},
{
"aid": 5,
"atext": "A source of thermal ionization that produces positive and negative ions that change the conductivity of the gas passing through the detector."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 54 | The electrolytic cells: | 3 | [
{
"aid": 1,
"atext": "They always have three electrodes."
},
{
"aid": 2,
"atext": "They always have two compartments separated by a salt bridge."
},
{
"aid": 3,
"atext": "They can have a single compartment."
},
{
"aid": 4,
"atext": "They always have a reference electrode."
},
{
"aid": 5,
"atext": "They always use platinum electrodes."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 55 | In some sample treatments, the solid phase extraction technique is used. Said technique: | 4 | [
{
"aid": 1,
"atext": "It has the advantage that solvents are not required."
},
{
"aid": 2,
"atext": "It is applied by contacting the solid sample with the stationary phase contained in a cartridge."
},
{
"aid": 3,
"atext": "It does not require the application of pressure or vacuum."
},
{
"aid": 4,
"atext": "It allows carrying out the preconcentration of large volume samples."
},
{
"aid": 5,
"atext": "It is characterized by the high consumption of solvents."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 56 | Which of the following transducers are not suitable in Atomic Mass Spectrometry? | 5 | [
{
"aid": 1,
"atext": "Electron multiplying channels."
},
{
"aid": 2,
"atext": "Faraday Cup"
},
{
"aid": 3,
"atext": "Photo plates."
},
{
"aid": 4,
"atext": "Scintillation detectors."
},
{
"aid": 5,
"atext": "Photomultiplier tubes."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 57 | The proteins can exhibit a fluorescent emission spectrum due to the presence of the following intrinsic fluorophores that absorb radiation in the UV-next region: | 2 | [
{
"aid": 1,
"atext": "Alanine, valine, glycine."
},
{
"aid": 2,
"atext": "Tryptophan, tyrosine, phenylalanine."
},
{
"aid": 3,
"atext": "Serine, methionine, asparagine."
},
{
"aid": 4,
"atext": "Cysteine, alanine, methionine."
},
{
"aid": 5,
"atext": "None of the above is correct, proteins never exhibit fluorescence."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 58 | In a potentiometry at zero intensity the electrode: | 3 | [
{
"aid": 1,
"atext": "Indicator always measures balance potentials."
},
{
"aid": 2,
"atext": "Indicator measures the half-wave potential."
},
{
"aid": 3,
"atext": "Indicator can measure a mixed potential."
},
{
"aid": 4,
"atext": "Reference is always a calomel platinum electrode."
},
{
"aid": 5,
"atext": "Indicator is always a platinum electrode."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 59 | A microelectrode is characterized by: | 1 | [
{
"aid": 1,
"atext": "Give answers in steady state."
},
{
"aid": 2,
"atext": "Always need an inert electrolyte."
},
{
"aid": 3,
"atext": "Always need a potentiostatic system."
},
{
"aid": 4,
"atext": "Do not need a reference electrode."
},
{
"aid": 5,
"atext": "Always need agitation."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 60 | A parameter of great importance in chromatography is the equivalent height of theoretical plate (H). The van Deemter equation describes the behavior of a filler column for gas-liquid chromatography, where H = A + (B / u) + Cu, so that: | 4 | [
{
"aid": 1,
"atext": "C is the parameter that is taken as a measure of the quality of the filling of the column."
},
{
"aid": 2,
"atext": "A is the coefficient that collects the contribution of longitudinal diffusion."
},
{
"aid": 3,
"atext": "B is the parameter that is related to the resistance to the transfer of matter that opposes the stationary phase."
},
{
"aid": 4,
"atext": "u is the linear velocity of the mobile phase."
},
{
"aid": 5,
"atext": "B is canceled in columns without filling."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 61 | Ethidium bromide is a molecule that has a very low fluorescence yield in solution. However, its quantum yield increases remarkably when: | 2 | [
{
"aid": 1,
"atext": "It is atomized."
},
{
"aid": 2,
"atext": "It is interspersed between consecutive base pairs of the DNA double helix."
},
{
"aid": 3,
"atext": "The aqueous solution containing it is oxygenated."
},
{
"aid": 4,
"atext": "It binds to a heavy metal forming a complex."
},
{
"aid": 5,
"atext": "It is oxidized by the action of the enzyme glucoxaoxidase."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 62 | Which of the following detectors is used in Infrared Spectroscopy? | 5 | [
{
"aid": 1,
"atext": "Photomultiplier tube."
},
{
"aid": 2,
"atext": "Flame ionization detector."
},
{
"aid": 3,
"atext": "Potentiostat."
},
{
"aid": 4,
"atext": "Proportional counter"
},
{
"aid": 5,
"atext": "Deuterated triglycine sulfate crystal."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 63 | The determination of mercury by the cold vapor generation technique is based on the reduction of mercury in acid solution and the entrainment of the elemental mercury obtained to the absorption cell for analysis by atomic absorption. The most commonly used reducers are: | 1 | [
{
"aid": 1,
"atext": "SnCl2, for inorganic mercury and Na BH4 for both organomercury compounds and inorganic mercury."
},
{
"aid": 2,
"atext": "Citrate, both for inorganic mercury, and organomercuriales."
},
{
"aid": 3,
"atext": "Glutathione, especially suitable for all mercury species."
},
{
"aid": 4,
"atext": "CaH2, for organomercurials and KMnO4 for inorganic mercury."
},
{
"aid": 5,
"atext": "Na2SO3, for all mercury species."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 64 | In chromatography, the dead time can be defined as: | 3 | [
{
"aid": 1,
"atext": "The time between the injection of a sample and the appearance of a solute peak in the detector."
},
{
"aid": 2,
"atext": "The factor that indicates the amount of time a solute spends in the stationary phase in relation to the time spent in the mobile phase."
},
{
"aid": 3,
"atext": "The time it takes for a non-retained species to pass through a chromatographic column."
},
{
"aid": 4,
"atext": "The time it takes for the analyte to pass through the chromatographic detector."
},
{
"aid": 5,
"atext": "The relationship between the average linear velocity and the packing length of the column."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 65 | It is very common the use of rotary valves of 6 doors or routes, alternately switchable, for the injection of samples in liquid chromatography of high resolution. Which of the following answers is correct? | 2 | [
{
"aid": 1,
"atext": "In the injection position, the mobile phase flow is maintained towards the column without passing through the loop."
},
{
"aid": 2,
"atext": "In the loading position, the loop in charge of housing the sample remains open to the atmosphere whereby the sample can be deposited by means of a syringe."
},
{
"aid": 3,
"atext": "In the loading position, the mobile phase flow is maintained towards the column by previously passing through the loop."
},
{
"aid": 4,
"atext": "In the loading position, the sample is inserted into the column without disturbing the moving phase step towards the loop."
},
{
"aid": 5,
"atext": "In the injection position, the entire internal volume of the loop is directed to the waste while the mobile phase carries the sample."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 66 | A particle charged in solution moves when it is placed in an electric field. The speed acquired by the solute under the influence of the applied voltage is the product of the apparent mobility of the solute and the applied field. With regard to this mobility, it can be stated that: | 4 | [
{
"aid": 1,
"atext": "A neutral particle of small size will have a smaller mobility than a neutral one of large size."
},
{
"aid": 2,
"atext": "A macromolecular polymer will have greater mobility than the corresponding monomer."
},
{
"aid": 3,
"atext": "A large particle with a small charge will have great mobility."
},
{
"aid": 4,
"atext": "A small particle of great load will have great mobility."
},
{
"aid": 5,
"atext": "A charged micelle will have less mobility than another micelle of the same size but neutral."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 67 | In the quantitative analysis by gas chromatography, to minimize the uncertainties that are introduced with the injection of the sample, the flow velocity and the variations in the conditions of the columns is used: | 5 | [
{
"aid": 1,
"atext": "Manual estimation of chromatographic peak heights."
},
{
"aid": 2,
"atext": "The normalization of the areas."
},
{
"aid": 3,
"atext": "The method of standard additions."
},
{
"aid": 4,
"atext": "An external calibration"
},
{
"aid": 5,
"atext": "The internal pattern method."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 68 | The use of monolithic columns and continuous beds in liquid chromatography is already very common. To this end: | 2 | [
{
"aid": 1,
"atext": "Microporous membranes are used so that the interaction between a solute and the matrix takes place in the final part of the pore."
},
{
"aid": 2,
"atext": "A separation medium is introduced with a greater degree of continuity than the stationary particle phase so that the mobile phase is forced to traverse the large pores of the medium, improving mass transport."
},
{
"aid": 3,
"atext": "Monodisperse particles are used as a stationary phase in order to improve mass transfer."
},
{
"aid": 4,
"atext": "Flexible organic gels are used from microporous polymers in order to decrease the flow rates."
},
{
"aid": 5,
"atext": "Columns filled with small particles of polymerized silica are used."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 69 | The pH that provides a 0.01 M solution of benzoic acid (pKa = 4.2) is: | 3 | [
{
"aid": 1,
"atext": "1.1."
},
{
"aid": 2,
"atext": "2.1."
},
{
"aid": 3,
"atext": "3.1."
},
{
"aid": 4,
"atext": "4.1."
},
{
"aid": 5,
"atext": "4.2."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 70 | In the technique of atomic absorption spectrometry, the use of an electrothermal atomizer instead of the flame provides: | 5 | [
{
"aid": 1,
"atext": "Greater accuracy"
},
{
"aid": 2,
"atext": "Greater precision."
},
{
"aid": 3,
"atext": "Greater sample consumption"
},
{
"aid": 4,
"atext": "Longer analysis times."
},
{
"aid": 5,
"atext": "Greater sensitivity"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 71 | The reactivity of various carbonyl groups is determined by their relative stability. The order of reactivity towards nucleophiles is: | 2 | [
{
"aid": 1,
"atext": "Amides> Esters> Ketones> Aldehydes."
},
{
"aid": 2,
"atext": "Aldehydes> Ketones> Esters> Amides."
},
{
"aid": 3,
"atext": "Amides> Ketones> Aldehydes> Esters."
},
{
"aid": 4,
"atext": "Aldehydes> Esters> Ketones> Amides."
},
{
"aid": 5,
"atext": "Amides> Ketones> Esters> Aldehydes."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 72 | The reaction of a halogenated derivative with triphenylphosphine leads to a salt of: | 5 | [
{
"aid": 1,
"atext": "Sulfonium."
},
{
"aid": 2,
"atext": "Diazonio."
},
{
"aid": 3,
"atext": "Ammonium."
},
{
"aid": 4,
"atext": "Pyridinium"
},
{
"aid": 5,
"atext": "Phosphonium"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 73 | The Baeyer-Villiger oxidation is an important procedure to transform ketones into: | 3 | [
{
"aid": 1,
"atext": "Acids"
},
{
"aid": 2,
"atext": "Aldehydes."
},
{
"aid": 3,
"atext": "Esters."
},
{
"aid": 4,
"atext": "Ethers"
},
{
"aid": 5,
"atext": "Alquenos"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 74 | Primary amines give condensation reactions with aldehydes and ketones producing: | 1 | [
{
"aid": 1,
"atext": "Iminas."
},
{
"aid": 2,
"atext": "Enaminas"
},
{
"aid": 3,
"atext": "Amides"
},
{
"aid": 4,
"atext": "Hydrazines"
},
{
"aid": 5,
"atext": "Purines."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 75 | The first stage of the mechanism of dehydration of cyclohexanol with H2SO4 is: | 3 | [
{
"aid": 1,
"atext": "Loss of OH-."
},
{
"aid": 2,
"atext": "Formation of an ester sulfate."
},
{
"aid": 3,
"atext": "Protonation of alcohol."
},
{
"aid": 4,
"atext": "Loss of H + by alcohol."
},
{
"aid": 5,
"atext": "Elimination of H2O from alcohol."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 77 | How many stereoisomers of 3-methylcyclohexane-1,2-diol can exist? | 5 | [
{
"aid": 1,
"atext": "Four."
},
{
"aid": 2,
"atext": "5."
},
{
"aid": 3,
"atext": "6"
},
{
"aid": 4,
"atext": "7"
},
{
"aid": 5,
"atext": "8"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 79 | The six-membered cyclic ether with an oxygen atom is called: | 2 | [
{
"aid": 1,
"atext": "Oxolane"
},
{
"aid": 2,
"atext": "Oxano"
},
{
"aid": 3,
"atext": "Dioxane"
},
{
"aid": 4,
"atext": "Oxirano."
},
{
"aid": 5,
"atext": "Oxetano."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 80 | The reaction of trans-2-butene with m-chloroperbenzoic acid (mCPBA) gives: | 4 | [
{
"aid": 1,
"atext": "A mixture of diastereoisomers."
},
{
"aid": 2,
"atext": "(R) -3-Cloroperbenzoate 2-butyl."
},
{
"aid": 3,
"atext": "cis-2,3-Dimethyloxacyclopropane."
},
{
"aid": 4,
"atext": "trans-2,3-Dimethyloxacyclopropane."
},
{
"aid": 5,
"atext": "() -3-Cloroperbenzoate 2-butyl."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 82 | The dehydrogenation of alkylbenzenes is not a convenient laboratory method, but it is used in an industrial way to convert ethylbenzene to: | 3 | [
{
"aid": 1,
"atext": "Cumeno"
},
{
"aid": 2,
"atext": "Toluene"
},
{
"aid": 3,
"atext": "Styrene"
},
{
"aid": 4,
"atext": "Phenol."
},
{
"aid": 5,
"atext": "Naphthalene"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 83 | Pyridazine is an aromatic heterocycle that contains in its structure: | 2 | [
{
"aid": 1,
"atext": "A nitrogen"
},
{
"aid": 2,
"atext": "Two nitrogens"
},
{
"aid": 3,
"atext": "Three nitrogens"
},
{
"aid": 4,
"atext": "Four nitrogens"
},
{
"aid": 5,
"atext": "No nitrogen"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 84 | In the oxaciclohexane-type conformer of sugar -D - (+) - glucopyranose: | 4 | [
{
"aid": 1,
"atext": "One of the OH- groups is axial, but the remaining substituents are equatorial."
},
{
"aid": 2,
"atext": "The CH2OH group is axial but the remaining groups are equatorial."
},
{
"aid": 3,
"atext": "All groups are axial."
},
{
"aid": 4,
"atext": "All groups are equatorial."
},
{
"aid": 5,
"atext": "The CH2OH group is equatorial but the remaining groups are axial."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 85 | When cyclopentanone is reacted with pyrrolidine, it forms: | 3 | [
{
"aid": 1,
"atext": "Amine."
},
{
"aid": 2,
"atext": "Amide."
},
{
"aid": 3,
"atext": "Enamina."
},
{
"aid": 4,
"atext": "Acetal"
},
{
"aid": 5,
"atext": "Oxima."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 86 | The reaction in which a vinyl halide or aryl reacts with a terminal alkyne in the presence of cuprous iodide and a Pd (0) catalyst is known as the reaction of: | 4 | [
{
"aid": 1,
"atext": "Suzuki"
},
{
"aid": 2,
"atext": "Heck"
},
{
"aid": 3,
"atext": "Stille"
},
{
"aid": 4,
"atext": "Sonogashira."
},
{
"aid": 5,
"atext": "Sharpless."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 87 | Histidine and histamine are two compounds with biological importance that have in common as a structural unit: | 5 | [
{
"aid": 1,
"atext": "Pyridine"
},
{
"aid": 2,
"atext": "Piperidine"
},
{
"aid": 3,
"atext": "Triazine"
},
{
"aid": 4,
"atext": "Phenol."
},
{
"aid": 5,
"atext": "Imidazole"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 88 | The reaction conditions for transforming nonanamide into octanamine and carbon dioxide are: | 3 | [
{
"aid": 1,
"atext": "H2, metallic catalyst."
},
{
"aid": 2,
"atext": "Excess of CH3I, K2 CO3."
},
{
"aid": 3,
"atext": "Cl2, NaOH, H2O."
},
{
"aid": 4,
"atext": "LiAlH4, diethyl ether and then hydrolysis."
},
{
"aid": 5,
"atext": "CH2N2, diethyl ether."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 89 | The number of nodes of the LUMO (unoccupied orbital of lower energy) of 1,3-butadiene is: | 3 | [
{
"aid": 1,
"atext": "None."
},
{
"aid": 2,
"atext": "One."
},
{
"aid": 3,
"atext": "Two."
},
{
"aid": 4,
"atext": "Three."
},
{
"aid": 5,
"atext": "Four."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 90 | The reaction of 3-methylcyclohex-2-enone with lithium dibutyl caprate and subsequent addition of chlorotrimethylsilane gives: | 1 | [
{
"aid": 1,
"atext": "[(3-Butyl-3-methylcyclohex-1-en-1-yl) oxy] trimethylsilane."
},
{
"aid": 2,
"atext": "[(1-Butyl-3-methylcyclohex-2-en-1-yl) oxy] trimethylsilane."
},
{
"aid": 3,
"atext": "Nothing."
},
{
"aid": 4,
"atext": "3-Butyl-3-methyl-2- (trimethylsilyl) cyclohexanone."
},
{
"aid": 5,
"atext": "[(6-Butoxy-3-methylcyclohex-1-en-1-yl) oxy] trimethylsilane."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 91 | The selectivity in the nucleophilic opening that occurs in the substituted oxacyclopropanes is called: | 3 | [
{
"aid": 1,
"atext": "Enantioselectivity"
},
{
"aid": 2,
"atext": "Diastereoselectivity."
},
{
"aid": 3,
"atext": "Regioselectivity"
},
{
"aid": 4,
"atext": "Mesoselectivity"
},
{
"aid": 5,
"atext": "None of them."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 92 | The reaction of 3-nitrobenzaldehyde with NaBH 4 in aqueous methanol gives: | 5 | [
{
"aid": 1,
"atext": "3-Aminobenzaldehyde."
},
{
"aid": 2,
"atext": "3-nitrobenzoic acid."
},
{
"aid": 3,
"atext": "1-Methyl-3-nitrobenzene."
},
{
"aid": 4,
"atext": "3-Nitrobenzoate sodium."
},
{
"aid": 5,
"atext": "(3-Nitrophenyl) methanol."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 93 | At 30 ° C, butylamine reacts with ethyl acrylate in KOH / EtOH and gives: | 3 | [
{
"aid": 1,
"atext": "N-Butylprop-2-enamide."
},
{
"aid": 2,
"atext": "Prop-2-potassium enoate."
},
{
"aid": 3,
"atext": "3- (Butylamino) ethyl propanoate."
},
{
"aid": 4,
"atext": "No new compound is formed."
},
{
"aid": 5,
"atext": "Butene, ethanol and prop-2-enamide."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 94 | Reactions that use copper (I) salts as reagents to replace the nitrogen in the diazonium salts are called reactions of: | 1 | [
{
"aid": 1,
"atext": "Sandmeyer"
},
{
"aid": 2,
"atext": "Chichibabin"
},
{
"aid": 3,
"atext": "Peterson."
},
{
"aid": 4,
"atext": "Gabriel."
},
{
"aid": 5,
"atext": "Diels-Alder."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 95 | The reactions in which the kinetics does not depend on the nucleophilic concentration, are reactions: | 2 | [
{
"aid": 1,
"atext": "Radicals"
},
{
"aid": 2,
"atext": "SN1."
},
{
"aid": 3,
"atext": "Pericyclic."
},
{
"aid": 4,
"atext": "SN2."
},
{
"aid": 5,
"atext": "None of the above."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 96 | The hydroxy acids can be esterified intramolecularly by forming: | 5 | [
{
"aid": 1,
"atext": "Lactams"
},
{
"aid": 2,
"atext": "Nitrones."
},
{
"aid": 3,
"atext": "Imidas"
},
{
"aid": 4,
"atext": "Carbamates."
},
{
"aid": 5,
"atext": "Lactones."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 97 | The reaction conditions for the preparation of 2-methyl-1-methoxypropan-2-ol from 2,2-dimethyloxirane are: | 4 | [
{
"aid": 1,
"atext": "The reaction with methanol in an acid medium."
},
{
"aid": 2,
"atext": "There is no effective synthetic route."
},
{
"aid": 3,
"atext": "The reaction with methylmagnesium bromide and subsequent hydrolysis."
},
{
"aid": 4,
"atext": "The reaction with sodium methoxide in methanol."
},
{
"aid": 5,
"atext": "The reaction with triphenylphosphine."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 98 | Cyclopentadiene is so reactive that leaving it at room temperature slowly dimerizes by a reaction of: | 2 | [
{
"aid": 1,
"atext": "Friedel-Crafts."
},
{
"aid": 2,
"atext": "Diels-Alder."
},
{
"aid": 3,
"atext": "Markovnikov."
},
{
"aid": 4,
"atext": "Suzuki"
},
{
"aid": 5,
"atext": "Gabriel."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 99 | Friedel-Crafts alkylation reactions lead to products that: | 3 | [
{
"aid": 1,
"atext": "They facilitate diazotization reactions."
},
{
"aid": 2,
"atext": "They facilitate the reactions of formation of ethers."
},
{
"aid": 3,
"atext": "Activate the aromatic ring against other substitutions."
},
{
"aid": 4,
"atext": "They deactivate the aromatic ring against other substitutions."
},
{
"aid": 5,
"atext": "None of the above."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 100 | The oxygen of the ethers as that of the alcohols can be protonated to generate: | 2 | [
{
"aid": 1,
"atext": "Iminium ion."
},
{
"aid": 2,
"atext": "Alkaloxonium ions."
},
{
"aid": 3,
"atext": "Peroxides"
},
{
"aid": 4,
"atext": "Piranos."
},
{
"aid": 5,
"atext": "Enaminas"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 101 | The organometallic react with the nitriles giving: | 4 | [
{
"aid": 1,
"atext": "Amino acids."
},
{
"aid": 2,
"atext": "Lactones."
},
{
"aid": 3,
"atext": "Alcohols"
},
{
"aid": 4,
"atext": "Ketones"
},
{
"aid": 5,
"atext": "None of the above."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 102 | Isopropyl alcohol is prepared from petroleum by hydration of: | 5 | [
{
"aid": 1,
"atext": "Isobutene"
},
{
"aid": 2,
"atext": "Eteno"
},
{
"aid": 3,
"atext": "Penteno"
},
{
"aid": 4,
"atext": "Buteno."
},
{
"aid": 5,
"atext": "Propene"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 103 | Isoprene is: | 1 | [
{
"aid": 1,
"atext": "2-methyl-1,3-butadiene."
},
{
"aid": 2,
"atext": "2-methyl-2-butene."
},
{
"aid": 3,
"atext": "2-methyl-1-butene."
},
{
"aid": 4,
"atext": "2-ethyl-1,3-butadiene."
},
{
"aid": 5,
"atext": "2-ethyl-2-butene."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 104 | What is the maximum number of stereoisomers of an aldohexose? | 4 | [
{
"aid": 1,
"atext": "two."
},
{
"aid": 2,
"atext": "Four."
},
{
"aid": 3,
"atext": "8"
},
{
"aid": 4,
"atext": "16"
},
{
"aid": 5,
"atext": "32"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 105 | The reaction of peroxycarboxylic acids with the carbonyl group of ketones produces: | 2 | [
{
"aid": 1,
"atext": "Acids"
},
{
"aid": 2,
"atext": "Esters."
},
{
"aid": 3,
"atext": "Alcohols"
},
{
"aid": 4,
"atext": "Ethers"
},
{
"aid": 5,
"atext": "Amides"
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 106 | The lithium aluminum hydride reacts with the carboxylic acids to give: | 5 | [
{
"aid": 1,
"atext": "Esters."
},
{
"aid": 2,
"atext": "Ketones"
},
{
"aid": 3,
"atext": "Tertiary alcohols."
},
{
"aid": 4,
"atext": "Secondary alcohols"
},
{
"aid": 5,
"atext": "Primary alcohols."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 107 | The groups with resonant electroacoustic effect are: | 2 | [
{
"aid": 1,
"atext": "Deactivators and ortho / para-leaders."
},
{
"aid": 2,
"atext": "Activators and ortho / para-leaders."
},
{
"aid": 3,
"atext": "Deactivators and meta-leaders."
},
{
"aid": 4,
"atext": "Activators and meta-leaders."
},
{
"aid": 5,
"atext": "Deactivators and do not orient to any position."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 108 | Which halogens react with methane by a radical chain reaction generating haloamines? | 3 | [
{
"aid": 1,
"atext": "Fluor and chlorine."
},
{
"aid": 2,
"atext": "Bromine and chlorine."
},
{
"aid": 3,
"atext": "Fluor, chlorine and bromine."
},
{
"aid": 4,
"atext": "Everyone."
},
{
"aid": 5,
"atext": "Iodo."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 109 | The reduction of nitriles with diisobutyl aluminum hydride (DIBAL) provides, after the corresponding aqueous acid treatment: | 4 | [
{
"aid": 1,
"atext": "Amines"
},
{
"aid": 2,
"atext": "Acids"
},
{
"aid": 3,
"atext": "ketones."
},
{
"aid": 4,
"atext": "Aldehydes."
},
{
"aid": 5,
"atext": "None of the above."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 110 | Markovnikov's rule predicts regioselectivity in the reactions of: | 3 | [
{
"aid": 1,
"atext": "Nucleophile substitution."
},
{
"aid": 2,
"atext": "Electrophilic aromatic substitution."
},
{
"aid": 3,
"atext": "Electrophilic addition."
},
{
"aid": 4,
"atext": "Nucleophilic addition."
},
{
"aid": 5,
"atext": "Oxidation of alcohols."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 111 | The lithium dialkyl-heptarate reacts with alkyl halides to produce, by formation of carbon-carbon bonds between the alkyl group of the halide and the alkyl group of the dialkyl acetate: | 1 | [
{
"aid": 1,
"atext": "Alcanes."
},
{
"aid": 2,
"atext": "Alquenos"
},
{
"aid": 3,
"atext": "Alquinos."
},
{
"aid": 4,
"atext": "Aromatics"
},
{
"aid": 5,
"atext": "Piranos."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 112 | The treatment of 1-hexyne with 1 mole of hydrogen bromide results in: | 4 | [
{
"aid": 1,
"atext": "1-bromo-1-hexene."
},
{
"aid": 2,
"atext": "1-bromo-2-hexene."
},
{
"aid": 3,
"atext": "1-bromo-3-hexene."
},
{
"aid": 4,
"atext": "2-bromo-1-hexene."
},
{
"aid": 5,
"atext": "2-bromo-2-hexene."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 113 | The chemistry of diazonium salts provides the main synthetic method for preparing aryl fluorides by a process called: | 5 | [
{
"aid": 1,
"atext": "Reorganization of Claisen."
},
{
"aid": 2,
"atext": "Gabriel's reaction."
},
{
"aid": 3,
"atext": "Diazotization reaction."
},
{
"aid": 4,
"atext": "Sandmeyer reaction."
},
{
"aid": 5,
"atext": "Schiemann reaction."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 114 | The terpene that contains 10 carbon atoms and is derived from two isoprene units is called: | 2 | [
{
"aid": 1,
"atext": "Diterpene"
},
{
"aid": 2,
"atext": "Monoterpene"
},
{
"aid": 3,
"atext": "Sesquiterpene"
},
{
"aid": 4,
"atext": "Triterpene"
},
{
"aid": 5,
"atext": "Meroterpeno."
}
] |
Cuaderno_2013_1_Q | 2013 | chemistry | 115 | Choose among the following phrases the one that most appropriately defines a concerted reaction: | 1 | [
{
"aid": 1,
"atext": "Reaction in a single stage in which all the links that are formed and break do so at the same time."
},
{
"aid": 2,
"atext": "Reaction in several stages in which all the links that are formed and break do so at the same time in the slowest stage."
},
{
"aid": 3,
"atext": "Reaction in which the speed of all stages is identical."
},
{
"aid": 4,
"atext": "It is an equilibrium reaction in which K = 1."
},
{
"aid": 5,
"atext": "Reaction in several stages in which all the links that are formed and break do so at the same time in the fastest stage."
}
] |
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