Answer. Some disadvantages of hard water are:
(i) Hard water consumes large amount of soap for washing purposes.
(ii) Drinking hard water causes stomach disorders.
(iii) Hard water is .unfit for use in steam engines, boilers and turbines because insoluble calcium and magnesium salts are deposited inside. They are bad conductors of electricity and hence more fuel is used. Insoluble calcium .and magnesium sulphates not only reduce the efficiency of the engine but also cause the boiler to burst,