Acids and Bases：練習題

When dilute nitric acid is added to a sample of solid calcium carbonate in a test tube, a gas is evolved. What is the correct test and observation for this gas?

A sample of ethanoic acid and a sample of hydrochloric acid of the same concentration are compared. Why does the hydrochloric acid react more vigorously with magnesium ribbon than the ethanoic acid?

Which of the following oxides is most likely to react with both aqueous sodium hydroxide and dilute nitric acid?

Which of the following substances will react with dilute hydrochloric acid to produce a salt and water as the only products?

A mixture of solid ammonium sulfate and aqueous sodium hydroxide is placed in a test tube and heated gently. Which of the following observations would be recorded?

Oxides are classified as acidic, basic, amphoteric, or neutral. Which of the following oxides is neutral and does not react with either dilute sulfuric acid or aqueous sodium hydroxide?

A. Carbon dioxide
B. Carbon monoxide
C. Calcium oxide
D. Zinc oxide

When an unknown solid Y is heated with aqueous calcium hydroxide, a gas is evolved that turns damp red litmus paper blue.

(a) Identify the cation present in solid Y.
(b) Construct the ionic equation, including state symbols, for the reaction occurring between the cation and the hydroxide ions.

A student is provided with two separate beakers: one contains 0.1 mol/dm\(^3\) ethanoic acid and the other contains 0.1 mol/dm\(^3\) hydrochloric acid.

(a) Explain, in terms of ionisation, why the pH of hydrochloric acid is lower than that of ethanoic acid despite having the same concentration.
(b) Describe a chemical test, other than using a pH meter or indicator, that could be used to distinguish between these two acids and state the expected observation for each.

A student is provided with two unknown colorless liquids, A and B. One is dilute sulfuric acid, and the other is dilute ethanoic acid. Both have a concentration of \( 0.5\text{ mol/dm}^3 \).

(a) Describe how the student can distinguish between the two acids using a pH meter. Explain your answer in terms of the extent of ionisation of the acids.
(b) The student adds a piece of magnesium ribbon of the same length to \( 20\text{ cm}^3 \) of each acid in separate test tubes. Compare the observations and explain the difference in the rate of gas evolution.
(c) Write a balanced chemical equation, including state symbols, for the reaction between magnesium and sulfuric acid.

Oxides can be classified into four types based on their chemical properties: acidic, basic, amphoteric, and neutral.

(a) Define an amphoteric oxide and provide two examples from the following list: \( SO_2, MgO, ZnO, CO, Al_2O_3, CaO \).
(b) Carbon monoxide \( (CO) \) is a neutral oxide. Describe how its reaction (or lack thereof) with aqueous sodium hydroxide and dilute hydrochloric acid confirms this classification.
(c) When nitrogen dioxide \( (NO_2) \) dissolves in water, it forms a mixture of nitric acid \( (HNO_3) \) and nitrous acid \( (HNO_2) \). Predict the effect of this solution on the pH of a soil sample and suggest a substance that could be added to the soil to neutralise the acidity, explaining the choice.