Topic 4 - Acids and Bases

A mixture of NH4Cl(aq) and ZnCl2(aq) is heated with excess NaOH(aq). Which of the following observations is correct?

• No pungent (刺激的） gas is evolved and no precipitate is formed.

• No pungent (刺激的） gas is evolved but a white precipitate is formed.

• A pungent (刺激的）gas is evolved but no precipitate is formed.

• A pungent (刺激的） gas is evolved and a white precipitate is formed.

Which of the following statements about dilute hydrochloric acid is INCORRECT？

• It is made by dissolving hydrogen chloride gas in water.

• It reacts with silver nitrate solution to give a white precipitate.

• It is used in car batteries.

• “CORROSIVE” label should be displayed on a bottle of dilute hydrochloric acid.

Answer explanation

The car batteries use sulphuric acid.

Which of the following substances are acidic?

(1) Window cleanser (2) Gastric juice胃酸 (3) Soft drink

• (1) and (2) only

• (1) and (3) only

• (2) and (3) only

• (1), (2) and (3)

Solid X reacts with dilute sulphuric acid. Water is NOT produced in the reaction. What might X be?

• Zinc hydroxide

• Magnesium oxide

• Potassium carbonate

• Calcium chloride

• A

• B

• C

• D

• A

• B

• C

• D

Which of the following experiments would produce a gas which turns limewater milky?

• Mixing magnesium carbonate with dilute hydrochloric acid

• Heating magnesium oxide with carbon

• Mixing zinc oxide with dilute nitric acid

• Mixing zinc oxide with carbon

Which of the following substances can react with dilute sulphuric acid?

(1) Barium hydroxide

(2) Nickel (II) oxide

(3) Zinc carbonate

• (1) and (2) only

• (1) and (3) only

• (2) and (3) only

• (1), (2) and (3)

Which of the following acids is a tribasic acid?

• Carbonic acid

• Nitric acid

• Phosphoric acid

• Sulphurous acid

• A

• B

• C

• D