The characteristic properties of acids and bases：練習題

What color change is observed when a few drops of methyl orange indicator are added to a solution of dilute hydrochloric acid?

Which products are formed when ammonium chloride is warmed with aqueous calcium hydroxide?

Equal volumes of \(0.1\text{ mol/dm}^3\) hydrochloric acid and \(0.1\text{ mol/dm}^3\) ethanoic acid are neutralised by \(0.1\text{ mol/dm}^3\) sodium hydroxide. Which statement is correct?

Which gas is produced when dilute nitric acid reacts with solid calcium carbonate?

A student warms an unknown colorless solution with aqueous sodium hydroxide. A gas is evolved that turns damp red litmus paper blue. Which ion is present in the solution?

Write the ionic equation that represents the neutralisation reaction between any strong acid and any strong alkali, including state symbols.

When an alkali is warmed with an ammonium salt, what gas is produced, and what is the characteristic test result for this gas?

In the following reversible reaction, identify which reactant acts as the proton donor according to the Brønsted-Lowry theory:
\(NH_3(aq) + H_2O(l) \rightleftharpoons NH_4^+(aq) + OH^-(aq)\).

Dilute sulfuric acid, $$ \text{H}_2\text{SO}_4 $$ , is a strong acid with characteristic properties.

Write a balanced symbol equation for the reaction of dilute sulfuric acid with each of the following substances. Include state symbols where appropriate.

(a) Zinc metal ( $$ \text{Zn} $$ )

(b) Aqueous sodium hydroxide ( $$ \text{NaOH} $$ )

(c) Solid copper(II) carbonate ( $$ \text{CuCO}_3 $$ )

A student tested two different solutions, Solution X and Solution Y, using universal indicator paper. Solution X turned the paper red ( $$ \text{pH}=2 $$ ) and Solution Y turned the paper blue ( $$ \text{pH}=10 $$ ).

(a) State the ion responsible for the acidic property of Solution X and the ion responsible for the alkaline property of Solution Y.

(b) Solution X is a strong acid and Solution Y is a strong alkali. Both solutions have the same concentration ( $$ 0.1 \text{mol}/\text{dm}^3 $$ ).

i) Which solution has a higher concentration of hydrogen ions ( $$ \text{H}^+ $$ )?

ii) Describe the colour change you would observe if Solution X was slowly added to Solution Y until neutralisation was complete, monitored using universal indicator paper.

(c) Write the balanced ionic equation, including state symbols, for the neutralisation reaction between Solution X and Solution Y.