All Free Chemistry MCQs with Answers

• A. SnO + 4NaOH --> Sn(OH)4 + 2Na2O
• B. SnO + 4NaOH --> Na4Sn (OH)4
• C. SnO + 2NaOH --> Na2Sn (OH)4
• D. None of the above

Explanation: The correct reaction for SnO and NaOH is: SnO + 2NaOH → Na2SnO2 + H2O. In this reaction, tin(II) oxide reacts with sodium hydroxide to…

• A. Isotropic
• B. Anisotropic
• C. good conductor of electricity
• D. Both (b) & (c)

Explanation: Graphite is one of the allotropic forms of carbon, and it is known to be anisotropic and a good conductor of electricity.

• A. A red precipitate of CuO is formed
• B. A black precipitate of CuO is formed
• C. Silver mirror is formed
• D. No reaction occurs

Explanation: Aldehyde reacts with Fehling reagent through the following reaction: Diagram This is an oxidation reaction in which copper oxidizes alkyl…

• A. CH3COOH
• B. C2H5OH
• C. OHC.OHC
• D. None of the above

Explanation: An aldehyde on oxidation with an oxidizing agent (such as one given in qs) gives its respective carboxylic acid. A is a carboxylic acid.

• A. Cu (I) oxide
• B. Ethanal
• C. Acetone
• D. Phenol

Explanation: Ethanal is an aldehyde and is capable of reducing Cu (ll) ions to Cu (l) ions. It will give a positive test with Fehling's solution.

• A. Hoffman reagent
• B. Grignard reagent
• C. Tollens reagent
• D. Cannizaro reagent

Explanation: Tollen's reagent, which is a solution of silver nitrate in aqueous ammonia, is used to test for the presence of aldehydes and…

• A. Talons test
• B. Fehling test
• C. Bacyer test
• D. Benedict test

Explanation: Bacyer's test is not used to identify aldehydes. Instead, it is used to detect the presence of unsaturation in organic compounds, such as…

• A. Benzaldehyde
• B. 2-Pentanone
• C. 3-Hexanone
• D. 3-Pentanone

Explanation: The iodoform test is a chemical reaction used to identify methyl ketones, which contain a CH3 group directly bonded to the carbonyl…

• A. Bacyer's test
• B. Fehling's test
• C. Silver mirror test
• D. Both (B) and (c)

Explanation: Both fehling's test and silver mirror test also known as tollens' test is used to distinguish between aldehydes and ketones.

• A. Propanone
• B. Ethanol
• C. Butanone
• D. Methanol

Explanation: It does not have methyl group attached to alpha carbon so it will not give idoform test

• A. Ethanol
• B. Ethanoic acid
• C. Ethane
• D. Ethylene

Explanation: H2/Ni are strong reducing agents which reduces aldehydes to primary alcohols and ketones to secondary alcohols.

• A. Acetone
• B. Ethyl acetate
• C. Formaldehyde
• D. Acetic acid

Explanation: Although both aldehydes and ketones contain the carbonyl functional group (-C=O), only aldehydes give a positive test (formation of an…

• A. Grignard reduction
• B. Clemmenson reduction
• C. Wolf-kishner reduction
• D. Friedel-craft reduction

Explanation: The Clemmensen reduction is a reaction that is used to reduce aldehydes or ketones to alkanes using hydrochloric acid and zinc amalgam.

• A. Acetophenon
• B. Phenylethanone
• C. Phenyl ethanal
• D. Phenylacetate

Explanation: The correct IUPAC name for the compound is 'Phenylethanone'. This compound is a ketone with a phenyl group attached to the carbonyl group…

• A. Acidified KMnO4
• B. Acidified K2Cr2O7
• C. Ag2O
• D. Both A and B

Explanation: The correct answer is Both A and B because both acidified KMnO4 and acidified K2Cr2O7 are strong oxidizing agents capable of oxidizing…

• A. Catalytic reduction
• B. Metal hydride
• C. Clemmensen method
• D. Lindlar's catalyst

Explanation: The carbon of the carbonyl group is reduced by metal hydrides. Metal hydrides, such as lithium aluminum hydride (LiAlH4) or sodium…

• A. CH2Cl-H2-COOH
• B. CHCl2COOH
• C. CH3 COOH
• D. CH3- CH2-COOH

Explanation: Many concepts are required to be cleared while solving these types of MCQsFirst, we should know, those acids are the strongest which can…

• A. they are polar molecules
• B. they form H-bonds
• C. they are stronger than mineral acids
• D. they have higher boiling points than their corresponding alcohols

Explanation: Mineral acids are stronger acids than carboxylic acids because mineral acids are completely ionized, whereas carboxylic acids are…

• A. Dichloroacetic acid
• B. Chloroacetic acid
• C. Formic acid
• D. Acetic acid

Explanation: Greater -I effect, due to the presence of two chloro groups increase the acid strength of dichloroacetic acid

• A. CH2Cl_CH2-COOH
• B. CHCl2_COOH
• C. CH3_COOH
• D. CH3-CH2-COOH

Explanation: In this case, the acidity of the carboxylic acids can be compared based on the stability of their corresponding conjugate bases.