All Free Chemistry MCQs with Answers

• A. Primary alcohols
• B. Teritary alcohol
• C. Secondary alcohols
• D. All

Explanation: Isobutyl alcohol and isopentyl alcohol are primary alcohols because the hydroxyl (-OH) group is attached to a carbon atom that is bonded…

• A. Alkaline aqueous I2
• B. K2Cr2O7 in dil. H2SO4
• C. Aqueous NaHCO3
• D. Na metal

Explanation: Methanol gets oxidized by acidified K2Cr2O7 but phenol does not.

• A. O2
• B. H2
• C. O
• D. H

Explanation: K2Cr2O7+ 4H2SO4 → K2SO4 + Cr(SO4)3 + 4H2O+3[O] This is an esterification reaction.

• A. C6H6ONa. .
• B. C7H6O
• C. C6H4OH
• D. C6H5ONa

Explanation: Phenol reacts with alkalis to form salts for example:

• A. Ketones
• B. Malonic acid
• C. Aldehydes
• D. Alkene

Explanation: Tertiary alcohols do not undergo oxidation with acidified potassium permanganate (KMnO4). They give no reaction.

• A. Organic acid
• B. Aldehyde
• C. Ether
• D. Ketone

Explanation: Option D is correct.Oxidation of secondary alcohols gives ketones. The oxidation of secondary alcohols is a two-step process.

• A. All of these features of college life have their place, and should receive the support of those students who is interested in them.
• B. All of these features of college life have its place, and should receive the support of those students who are interested in them.
• C. All of these features of college life has their place, and should receive the support of those students who are interested in them.
• D. All of these features of college life have their place, and should receive the support of those students who are interested in them.

Explanation: All of these features of college life have their place, and should receive the support of those students who are interested in them.

• A. There was a continual cracking noise that was the wood of the trunk splitting.
• B. There was a continual cracking noise that was wood of the trunk splitting.
• C. There was a continual cracking noise that was a wood of the trunk splitting.
• D. There was continual cracking noise that was the wood of trunk Splitting.

Explanation: The sentence is structured correctly, using the phrase "the wood of the trunk splitting" to indicate the source of the noise.

• A. Jan asked; "What did Joe mean when he said, 'I will see you later.'"
• B. Jan asked, "What did Joe mean when he said, 'I will see you later?'"
• C. Jan asked, "What did Joe mean when he said, 'I will see you later'?"
• D. Jan asked, "What did Joe mean when he said, 'I will see you later'"?

Explanation: It places the question mark correctly inside the double quotation marks, indicating that the entire sentence is a question, but outside…

• A. Grignard reagent
• B. Tollen's reagent
• C. Fehling's reagent
• D. Sodium nitroprusside

Explanation: The carboxyl group of both aldehydes and ketones can react with Grignard reagents to give alcohols.

• A. Manufacture of dyes
• B. Silvering of mirror
• C. Making formamint
• D. Antiseptic inhalent

Explanation: Uses of Fomaldehyde(i) It is used in the manufacture of resins like urea-formaldehyde and plasticssuch as bakelite.(ii) It is used in the…

• A. Acetaldehyde
• B. Acetone
• C. Butanone
• D. 3-pentanone

Explanation: Iodoform Test:The haloform reaction using iodine and aqueous sodium hydroxide is calledthe iodoform test.

• A. Grignard reagent
• B. Tollen's reagent
• C. Fehling's reagent
• D. Benedict's reagent

Explanation: Grignard reagents add to aldehydes and ketones to form adducts which on hydrolysis with a dilute mineral acid (HCI, H2SO4) give alcohols.

• A. Sugars
• B. Menthone
• C. Camphor
• D. Formamint

Explanation: Both ketones and aldehydes are present in sugars. Monosaccharides which contain an aldehyde group are known as aldoses, and those with a…

• A. H2SO4
• B. K2Cr207
• C. NaOH
• D. H20/H+

Explanation: Option C is correct since the aldol reaction happens in aldehydes and ketones if the compounds contain no less than one α-hydrogen.

• A. Formaldehyde
• B. Acetaldehyde
• C. Benzaldehyde
• D. Trimethyl acetaldehyde

Explanation: Cannizzaro's reaction is not given by aldehydes and ketones that have alpha hydrogen (hydrogen next to carbonyl carbon).

• A. Formaldehyde is a gas at room temperature
• B. Formaldehyde is a liquid at room temperature
• C. Oxidation of methyl alcohol can produce formaldehyde
• D. Dry distillation of calcium formate can produce formaldehyde:

Explanation: This is incorrect. Formaldehyde is a gas at room temperature.

• A. 10% solution of formaldehyde in water
• B. 20% solution of formaldehyde in water
• C. 40% solution of formaldehyde in water
• D. 60% solution of formaldehyde in water

Explanation: Correct: Formalin is a 40% aqueous solution of formaldehyde

• A. Formic acid
• B. Formaldehyde
• C. Furfuraldehyde
• D. Acetone

Explanation: Formalin is a aqueous solution consisting of about 40% formaldehyde.

• A. CHCl3
• B. Cl3CCHO
• C. CHI4
• D. ClCH2CH2Cl

Explanation: This compound, also known as trichloroacetaldehyde or chloral hydrate, is the correct option.