(a) When is a sample of water said to be hard?
(b) State one difference between temporary and permanent hardness of water
(c) Give one method of removing hardness completely from water
(d) Name two local is used for the production of soap.
Explanation
(a) Water is said to be hard when it does not easily lather with soap.
(b) Temporary hardness of water can be removed by heating the water while permanent hardness cannot be removed by heating.
(c) Addition of sodium trioxocarbonate (IV) into the water can effect the complete removal of hardness
(d) Palm oil and ash.