A sample of barium oxide is added to distilled water at 25 °C. A colourless solution forms containing barium hydroxide, Ba(OH)2\text{Ba(OH)}_2Ba(OH)2.
The solution is made up to 250.0 cm3250.0\text{ cm}^3250.0 cm3 with distilled water. The pH of this solution is 13.1513.1513.15.
Determine the mass of barium oxide that was used. Give your answer to 3 significant figures.
10 cm310\text{ cm}^310 cm3 of dilute sodium sulfate solution is added to 10 cm310\text{ cm}^310 cm3 of the colourless solution of Ba(OH)2\text{Ba(OH)}_2Ba(OH)2. Write an ionic equation, including state symbols, for the precipitation reaction.
199 exam-style questions on OCR A A Level Chemistry Atoms and reactions, covering Atomic structure and isotopes, Compounds, formulae and equations, Amount of substance, Acids, and Redox. Each one has a worked solution and a mark scheme showing where the marks go.