Question 1

What is the pH value of a neutral solution at 25°C?

Accepted Answer

A neutral solution has equal concentrations of H⁺ and OH⁻ ions, which corresponds to a pH of 7.

Question 2

Which of the following substances is a strong acid?

Accepted Answer

Hydrochloric acid (HCl) completely dissociates in water and is classified as a strong acid, unlike weak acids like acetic acid.

Question 3

What is the chemical formula of table salt produced when hydrochloric acid reacts with sodium hydroxide?

Accepted Answer

The neutralization reaction between HCl and NaOH produces sodium chloride (NaCl) and water: HCl + NaOH → NaCl + H₂O.

Question 4

A solution has a pH of 9. Is this solution acidic, basic, or neutral?

Accepted Answer

A pH greater than 7 indicates a basic (alkaline) solution because it has more OH⁻ ions than H⁺ ions.

Question 5

What is the pH value of a neutral solution at 25°C?

Accepted Answer

A neutral solution has equal concentrations of H⁺ and OH⁻ ions, which corresponds to a pH of exactly 7 at 25°C.

Question 6

Which of the following is a strong acid commonly used in laboratories?

Accepted Answer

Sulfuric acid (H₂SO₄) is a strong acid that completely ionizes in water, whereas acetic, carbonic, and citric acids are weak acids.

Question 7

When an acid reacts with a base, the products formed are always a salt and:

Accepted Answer

The neutralization reaction between an acid and a base always produces a salt and water as the two main products.

Question 8

Which salt is produced when hydrochloric acid reacts with sodium hydroxide?

Accepted Answer

HCl + NaOH → NaCl + H₂O; the salt produced is sodium chloride (common table salt).

Question 9

A solution with pH 3 is how many times more acidic than a solution with pH 6?

Accepted Answer

pH is logarithmic; each unit decrease represents a 10-fold increase in acidity, so pH 3 is 10³ = 1000 times more acidic than pH 6.

Question 10

A solution has a pH of 2. What is its hydrogen ion concentration [H⁺] in mol/L?

Accepted Answer

pH = -log[H⁺], so [H⁺] = 10⁻pH = 10⁻² = 0.01 mol/L.

Question 11

When sodium carbonate solution is added to calcium chloride solution, a white precipitate forms. What is the name of this white precipitate?

Accepted Answer

The reaction CaCl₂ + Na₂CO₃ → CaCO₃↓ + 2NaCl produces insoluble calcium carbonate as a white precipitate.

Question 12

A salt is formed by the reaction of a weak acid and a strong base. The resulting salt solution will be:

Accepted Answer

Salts of weak acids and strong bases hydrolyze to produce OH⁻ ions, making the solution basic.

Agniveer Army Clerk SKT Acids, Bases & Salts

Acids, Bases & Salts — Practice Questions