This question is about acids and bases.
Give the chemical formula of the ion that is responsible for making an aqueous solution alkaline.
A student performs a titration using barium hydroxide solution and dilute hydrochloric acid.
The chemical equation for this neutralisation reaction is:
Ba(OH)2(aq)+2HCl(aq)→BaCl2(aq)+2H2O(l) \text{Ba(OH)}_2(\text{aq}) + 2\text{HCl}(\text{aq}) \rightarrow \text{BaCl}_2(\text{aq}) + 2\text{H}_2\text{O}(\text{l}) Ba(OH)2(aq)+2HCl(aq)→BaCl2(aq)+2H2O(l)During the titration, 25.0 cm325.0\text{ cm}^325.0 cm3 of 0.120 mol/dm30.120\text{ mol/dm}^30.120 mol/dm3 barium hydroxide solution is completely neutralised by 22.4 cm322.4\text{ cm}^322.4 cm3 of hydrochloric acid.
Calculate the concentration of the hydrochloric acid in mol/dm3\text{mol/dm}^3mol/dm3. Give your final answer to 3 significant figures.
To find this, you should calculate:
Aqueous hydrochloric acid with a pH 2.5\text{pH } 2.5pH 2.5 has a hydrogen ion concentration of 3.16×10−3 mol/dm33.16 \times 10^{-3}\text{ mol/dm}^33.16×10−3 mol/dm3.
What is the concentration of H+\text{H}^+H+ ions in a solution of hydrochloric acid with pH 4.5\text{pH } 4.5pH 4.5?
40 exam-style questions on AQA GCSE Chemistry 4.2 Reactions of acids, covering 4.2.1 Reactions of acids with metals, 4.2.2 Neutralisation of acids and salt production, 4.2.3 Soluble salts, 4.2.4 The pH scale and neutralisation, 4.2.5 Titrations, and 4.2.6 Strong and weak acids (HT only). Each one has a worked solution and a mark scheme showing where the marks go.