Calcium oxide, CaO\text{CaO}CaO, is a white ionic solid.
Describe the ions present in calcium oxide by stating:
Calcium oxide reacts with water to form an aqueous solution of calcium hydroxide. Write the balanced symbol equation for this reaction, including state symbols.
Which ion is responsible for the alkaline properties of solutions of alkalis?
A salt is made when calcium hydroxide neutralises hydrochloric acid. Name this salt.
A sample of hydrochloric acid has a pH of 1.651.651.65.
A student adds water to the hydrochloric acid until the pH is 5.655.655.65.
The concentration of hydrogen ions decreases.
Calculate the factor by which the hydrogen ion concentration has decreased.
55 exam-style questions on OCR GCSE Chemistry Types of chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.