A technician dilutes hydrochloric acid with pure water to prepare a solution for a laboratory experiment. Hydrochloric acid is a strong acid.
| Solution | pH |
|---|---|
| Before dilution | 2 |
| After dilution | 3 |
State whether the concentration of hydrogen ions increases or decreases during the dilution.
Calculate the factor by which the hydrogen ion concentration changes during the dilution.
The volume of the solution before dilution is 250 cm3.
Calculate the total volume of the solution after dilution.
A separate sample of hydrochloric acid is neutralised using sodium hydroxide solution.
Write the balanced symbol equation for this reaction. Include state symbols.
Name the spectator ions in this neutralisation reaction.
In another test, more sodium hydroxide solution is added than is needed to neutralise the hydrochloric acid.
State which reacting ion remains in excess.
112 exam-style questions on OCR GCSE Chemistry 3.3 Types of chemical reactions, covering 3.3.1 Oxidation and reduction in terms of oxygen, 3.3.2 Acids, alkalis and neutralisation, 3.3.3 The pH scale and measuring pH, 3.3.4 Oxidation and reduction in terms of electrons, 3.3.5 Dilute and concentrated, weak and strong acids, and 3.3.6 Hydrogen ion concentration and pH. Each one has a worked solution and a mark scheme showing where the marks go.