Raju noticed that while washing clothes by using rain water collected in a tank, the quantity of soap required was found to be less than that required using tap water.
a. If Raju asked the reason behind it, how will you explain it?
b. Also mention any two methods to overcome.it,

While washing clothes by using rain water collected in a tank, the quantity of soap required was found to be less than that required using tap water. What may be the reason?

i) Rain water and séa, water differ in their behaviour towards soap. Give the difference and establish the chemistry behind this. ii) A water boiler in a factory burst due to high interior pressure. It was reported that the incident was occured due to certain dissolved salt in water used, As a chemistry student how will you explain this?