Chemistry

Test

Compound ‘A’ was prepared by oxidation of compound ‘B’ with alkaline KMnO4. Compound ‘A’ on reduction with lithium aluminium hydride gets converted back to compound ‘B’. When compound ‘A’ is heated with compound B in the presence of H2SO4 it produces the fruity smell of compound C to which family the compounds ‘A’, ‘B’ and ‘C’ belong to?

Solution: Compound ‘A’ belongs to the carboxylic acid. Compound ‘B’ belongs to alcohol. Compound ‘C’ belongs to an ester group.

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Temperature dependence of resistivity ρ(T) of semiconductors, insulators, and metals is significantly based on the following factors:
a) number of charge carriers can change with temperature T
b) time interval between two successive collisions can depend on T
c) length of material can be a function of T
d) mass of carriers is a function of T

The correct answer is a) number of charge carriers can change with temperature T b) time interval between two successive collisions can depend on T

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The correct order of increasing acidic strength is _____________. (i) Phenol < Ethanol < Chloroacetic acid < Acetic acid (ii) Ethanol < Phenol < Chloroacetic acid < Acetic acid (iii) Ethanol < Phenol < Acetic acid < Chloroacetic acid (iv) Chloroacetic acid < Acetic acid < Phenol < Ethanol

Solution: Option (iii) is the answer. Reason: The correct order of increasing acidic strength is Ethanol < Phenol < Acetic acid < Chloroacetic acid. Phenol is more acidic than ethanol...

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Under which of the following reaction conditions, aniline gives p-nitro derivative as the major product?
(i) Acetyl chloride/pyridine followed by reaction with conc. H2SO4 + conc. HNO3
(ii) Acetic anhydride/pyridine followed by conc. H2SO4 + conc. HNO3
(iii) Dil. HCl followed by reaction with conc. H2SO4 + conc. HNO3
(iv) Reaction with conc. HNO3 + conc.H2SO4

Solution: Option (i) and (ii) are the answers. Reason: In addition to the nitro derivatives, direct nitration of aniline produces tarry oxidation products. Furthermore, in a strongly acidic...

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Which of the following methods of preparation of amines will not give the same number of carbon atoms in the chain of amines as in the reactant?
(i) The reaction of nitrite with LiAlH4.
(ii) The reaction of the amide with LiAlH4 followed by treatment with water.
(iii) Heating alkyl halide with potassium salt of phthalimide followed by hydrolysis.
(iv) Treatment of amide with bromine in the aqueous solution of sodium hydroxide.

Solution: Option (iv) is the answer. Reason: In Hoffmann Bromide degradation as the word, suggest, the amide is reduced to an amine with 1- carbonless, so this is the method in which we don't get...

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Identify the correct statement from the following :
(1) Blister copper has blistered appearance due to evolution of CO2.
(2) Vapour phase refining is carried out for Nickel by Van Arkel method.
(3) Pig iron can be moulded into a variety of shapes.
(4) Wrought iron is impure iron with 4% carbon.

Correct option: (3) Explanation: Because of the evolution of $SO_2$, not $CO_2$, blister copper has a blistered appearance. The Van Arkel method is used to obtain ultra-pure Titanium through vapor...

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Identify the incorrect statement.
(1) The transition metals and their compounds are known for their catalytic activity due to their ability to adopt multiple oxidation states and to form complexes.
(2) Interstitial compounds are those that are formed when small atoms like H , C or N are trapped inside the crystal lattices of metals.
(3) The oxidation states of chromium in CrO _{4}^{2-} and Cr _{2} O _{7}^{2-} are not the same.
(4) Cr ^{2+}\left( d ^{4}\right) is a stronger reducing agent than Fe ^{2+}\left( d ^{6}\right) in water.

Correct option (3) Explanation: Interstitial compounds are those formed when small atoms such as H, B, C, or N are trapped inside metal crystal lattices. Fact: On the basis of standard reduction...

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