All Free Biology MCQs with Answers

• A. Formic acid
• B. Acetic acid
• C. Benzoic acid
• D. Amino acid

Explanation: Acetic acid is a colorless, clear liquid with a strong sour smell. It is also known as ethanoic acid or vinegar acid. Vinegar is a solution of acetic acid in water, typically containing 4-8% acetic acid by volume. Acetic acid is the most common carboxylic acid used as vinegar.

• A. Small sizes
• B. Polarity of C-O bond
• C. H-bonding
• D. Dipole-dipole interactions

Explanation: The primary factor that contributes to the formation of carboxylic acid dimers is hydrogen bonding. Hydrogen bonding is a strong interaction that occurs between a hydrogen atom that is bonded to a highly electronegative atom, such as oxygen, and another electronegative atom.

• A. Alcohol
• B. Aldehyde
• C. Ketone
• D. All of these

Explanation: The oxidation of alcohols, aldehydes, and ketones can form carboxylic acids. This can be carried out using a variety of oxidizing agents, including potassium dichromate, potassium permanganate, and nitric acid. The specific oxidizing agent used will depend on the substrate and the desired product.

• A. Oxalic acid
• B. Methanoic acid
• C. Glutaric acid
• D. Adipic acid

Explanation: A monocarboxylic acid only has 1 carboxyl group. Methanoic acid has only 1 carboxyl group.

• A. Apples
• B. Butter
• C. Ant's sting
• D. Foam

Explanation: Formic acid is obtained from ants sting. It is a colorless, pungent liquid that is the simplest carboxylic acid. It is also known as methanoic acid and has the chemical formula HCOOH.

• A. Concentration of products
• B. Time
• C. Concentration of substrate
• D. Concentration of solvent

Explanation: The rate of enzyme action is directly proportional to the concentration of the substrate. This is because the more substrate there is, the more enzyme molecules can bind to it and catalyze the reaction. The rate of enzyme action is not directly proportional to the concentration of products, time, or concentration of solvent.

• A. Hexokinase
• B. Glucose kinase
• C. Fructose kinase
• D. Malonic acid

Explanation: The enzyme that catalyzes the conversion of hexoses to 6-phosphate derivatives is hexokinase. Malonic acid is not an enzyme, and glucose kinase and fructose kinase are enzymes that catalyze the conversion of glucose and fructose to 6-phosphate derivatives, respectively.

• A. Aldehydes
• B. Ketones
• C. Carboxylic acids
• D. Alcohols

Explanation: The compounds having the -COOH group are called carboxylic acids.

• A. Salt + water
• B. Salt
• C. Salt + H2 gas
• D. Salt + Alcohol

Explanation: When metals react with carboxylic acids, they produce salts and hydrogen gas. The reaction is called acid-base neutralization.The general reaction is:metal + carboxylic acid → salt + hydrogen gas

• A. Acetic acid
• B. Butyric acid
• C. Propanoic acid
• D. All of these

Explanation: Formic acid is used as a coagulant for latex in the rubber industry.