A sample of strontium oxide is added to distilled water at 25 °C. A colourless solution forms containing strontium hydroxide, Sr(OH)2\text{Sr(OH)}_2Sr(OH)2.
The solution is made up to 500.0 cm3500.0\text{ cm}^3500.0 cm3 with distilled water. The pH of this solution is 12.8512.8512.85.
Determine the mass of strontium oxide that was used. Give your answer to 3 significant figures.
10 cm310\text{ cm}^310 cm3 of dilute sulfuric acid is added to 10 cm310\text{ cm}^310 cm3 of the colourless solution of Sr(OH)2\text{Sr(OH)}_2Sr(OH)2. Write an ionic equation, including state symbols, for the precipitation reaction.