What are the two main ways in which common salt (sodium chloride) occurs in nature?

16

What is the common name of

(a) NaHCO₃ or Na₂CO₃.10H₂O?

17

Write the chemical name and formula of (a) common salt, and

(b) caustic soda.

19

Name the major salt present in sea- water.

20

How is common salt obtained from sea-water?