Among Elements Chlorine Nitrogen And Sulphur Select

(i) Among the elements chlorine, nitrogen and sulphur select: (a) The least reactive. (b) Obtained from the … ? (iii) How can you get …

Answers:

(i) (a) Nitrogen. (b) Nitrogen.
(ii) Commercial nitric acid is brown in colour because it contains dissolved nitrogen dioxide.
(iii) CO2 and moisture-free air is passed through a condenser. Finally, this air is compressed, cooled and suddenly allowed to expand. By repeating this process, the air can be liquified.