Question

The time required for the mixing of lime and soda in lime soda process is _____________

(a) 10min

(b) 20min

(c) 40min

(d) 80 min

I have been asked this question in final exam.

Question is from Lime Soda Process topic in portion Water Softening of Environmental Engineering

Answer 1

Right answer is (c) 40min

To explain: The time required for the mixing of lime and soda in water in lime soda process is between 30-60min to allow completion of the chemical reaction. Precipitated chemicals are removed by sedimentation or filtration or both.