Question

The temperature at which the softening of water takes place by lime soda process is ____________

(a) 10^o-21^oC

(b) 20^o-30^oC

(c) 39^o-45^oC

(d) 90^oC

I had been asked this question in a national level competition.

This question is from Lime Soda Process topic in section Water Softening of Environmental Engineering

Answer 1

The correct option is (a) 10^o-21^oC

To explain I would say: The lime soda process can be operated continuously or intermittently at either 10^o-21^oC or at 100^oC.