Describe two ways in which sample A and sample B differ in composition.
Which positive ion has the smallest concentration in sample B?
Calculate the mass of chloride ions in $100\text{ cm}^3$ of sample B. Show your working clearly. $1\text{ dm}^3 = 1000\text{ cm}^3$.
Describe a test for chloride ions. State both the test and the result.
Which of these statements gives the best description of Brownian motion? Tick one box.
Explain why silicon(IV) oxide is an acidic oxide.
Describe how the concentration of dissolved oxygen changes as temperature changes.
Determine the concentration of oxygen in the water at $10^\circ\text{C}$.
Suggest how the rate of corrosion of iron water pipes changes with temperature. Explain your answer.
Describe how water is processed to make it safe to drink.
State one source of oxides of nitrogen in the air.
State one harmful effect of oxides of nitrogen on health.