All Free Chemistry MCQs with Answers

• A. HCOOH (Formic Acid)
• B. CH3CH2COOH (Propanoic Acid)
• C. CH3OCH3 (Diethyl Ether)
• D. CH3COOH (Acetic Acid)

Explanation: The correct answer is CH3OCH3 (Diethyl Ether). Diethyl ether does not contain an active hydrogen atom that sodium can displace, unlike…

• A. 1-Pentene
• B. 3-Pentene
• C. 2-Methylbutane
• D. 3-Methylbutane

Explanation: The major product is 2-pentene because it is the most stable alkene formed after carbocation rearrangement and follows Zaitsev's rule.

• A. C2H5OC2H5 + H2O
• B. C2 H4
• C. C2 H5 OH
• D. C2 H6

Explanation: At 140°C in the presence of sulfuric acid two molecules of ethanol are dehydrated (lose a molecule of water) to form ether.

• A. A) CH3CH2OH + HCl --> CH3CH2Cl + H2O
• B. B) CH3CH2OH + HBr --> CH3CH2Br + H2O
• C. C) CH3CH2OH + HI --> CH3CH2I + H2O
• D. D) Both B & C

Explanation: The correct answer is Option D The reaction of ethanol with HBr generally does not require a ZnCl2 catalyst because HBr is a more reactive…

• A. Aldehyde
• B. Ketone
• C. Ether
• D. None of the above

Explanation: A tertiary alcohol can't form this carbonyl group: the tertiary custom has three single bonds to other C- atoms and one single bond to the…

• A. They contain more alkyl group
• B. They have no alpha-hydrogen
• C. Suitable oxidizing agent is not available
• D. None of the above

Explanation: Tertiary alcohols are not oxidized by acidified sodium or potassium dichromate(VI) solution - there is no reaction whatsoever.

• A. 2,3 - Butanediol
• B. 1,2 - Butanediol
• C. 2-Methyl-1,2-Propandiol
• D. All of them

Explanation: Epoxide obtained from isobutylene is further hydrolyzed in the presence of acid The final product is 2-Methyl-1,2-Propandiol

• A. 2 - Butanol
• B. 1 - Butanol
• C. 2 - Methyle → 2 - Proponal
• D. All of these have the same boiling point

Explanation: Among the isomeric alcohols you mentioned, 1-butanol has the highest boiling point because it has a longer carbon chain, which allows for…

• A. Per Iodic acid
• B. Lad tetra acetate
• C. Acidified KMNO4
• D. Both (A) (B)

Explanation: When periodic acid (HIO4) reacts with ethylene glycol, it actually oxidizes ethylene glycol into a compound called glycolic acid, not…

• A. Ethene
• B. Ether
• C. Ethyl hydrogen sulphat
• D. None of the above

Explanation: When ethanol is dehydrated with concentrated sulfuric acid (conc MO) at a temperature of 140°C, it undergoes a chemical reaction called…

• A. 10 Alcohol
• B. 20 Alcohol
• C. 30 Alcohol
• D. Carboxylic acid

Explanation: When CH3MgBr, which is methylmagnesium bromide, reacts with CH2O, which is formaldehyde, it undergoes a nucleophilic addition reaction.

• A. Vic - diol
• B. Gem - diol
• C. Triol
• D. None of these

Explanation: Trimethylene glycol, also known as 1,3-propanediol, is a vicinal diol. In a vicinal diol, the hydroxyl (-OH) groups are attached to…

• A. Methyl alcohol
• B. Ethyl alcohol
• C. Benzyl alcohol
• D. P - cresol

Explanation: An aromatic alcohol is an alcohol that contains an aromatic ring, such as a benzene ring, with a hydroxyl group (-OH) attached.

• A. Alkyl chloride
• B. Acid chlorides
• C. Aldehydes
• D. Ketones

Explanation: The appearance of cloudiness in the Lucas test for alcohols is due to the formation of alkyl chloride.

• A. Cracking
• B. Reforming
• C. Polymerisation
• D. Condensation

Explanation: As we see, just straight-chain alkane is converted into branched-chain alkane, nothing else and this conversion is called Reforming.

• A. Methanol
• B. Propane
• C. Ethylene
• D. Benzene

Explanation: Upon complete oxidation, propane (C3H8 ) gives 4 moles of water:C3H8+5O2→3CO2+4H2O

• A. Methane
• B. Methylamine
• C. Ethylamine
• D. Methyl chloride

Explanation: When methyl magnesium chloride reacts with ammonia, the product obtained is methane.

• A. C6H14
• B. C6H12
• C. C6H10
• D. C6H0

Explanation: C6H12 follows the formula CnH2n, which is the general formula for cycloalkanes.

• A. Methane
• B. Methyl amine
• C. Ethyl amine
• D. Methyl chloride

Explanation: CH3-Mg-Cl +NH3 ---------> CH4 + NH2MgCl Grignard reagent/methyl magnesium chloride is basic in nature so it will accept H+ from ammonia…

• A. Consumption of fuel
• B. Price of fuel
• C. The octane number of fueL
• D. Knocking of engine

Explanation: The addition of Pb(C2H5)4 in gasoline reduces knocking in the engine by increasing the octane number of fuel.