10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of a given solution of HCl. If we take 20 mL of the same solution of NaOH, the amount HCl solution (the same solution as before) required to neutralise it will be :

A solution reacts with crushed egg-shells to give a gas that turns lime-water milky. The solution contains :

A solution turns red litmus blue, its pH is likely to be : (a) 1 (b) 4 (c) 5 (d) 10

Write an equation to show the reaction between Plaster of Paris and water.

What will happen if a solution of sodium hydrogen carbonate is heated? Give the equation of the reaction involved.

Name the sodium compound which is used for softening hard water.