(a) (i)Name the class of oxides to which copper (II) oxide belongs. (ii) Give the reason why copper (II) oxide increases in mass on exposure to the atmosphere (iii) Write an equation to show the action of dilute hydrochloric acid on copper (II) oxide.
(b) List two methods of removing total hardness from water.
Explanation
(a)(i) Basic oxide (ii) It is hygroscopic or absorbs water from atmosphere on exposure (but does not form solutions) (iii) CuO + 2HCI --> CuCl\(_2\) + H\(_2\)O
(b)(i) Use of washing soda (ii) Use of ion-exchange resin/permutit process (iii) Distillation or fractional distillation.
