2007 General Studies, all questions

UPSC Prelims 2007 · General Studies

Question 121: Science and Technology

Which one of the following is called Philosopher’s wool?

aZinc Bromide
bZinc Nitrate
cZinc Oxide
dZinc Chloride

AnswerThe answer is (c).

Zinc oxide is called philosopher's wool (or nil album): when zinc burns in air, it forms white woolly flakes of ZnO. It is amphoteric, and is used in ointments, paints and rubber. Zinc bromide, nitrate and chloride are different salts. Remember: philosopher's wool is zinc oxide.

Why each option is right or wrong
  • (a) Zinc bromide is a salt, not philosopher's wool.
  • (b) Zinc nitrate is a salt, not philosopher's wool.
  • (c) Correct: zinc oxide is philosopher's wool.
  • (d) Zinc chloride is a salt, not philosopher's wool.

Explanation: written by UPSC Grade, not by UPSC.

Practise this paper timedPrevious questionNext question

Source: UPSC, Civil Services (Preliminary) Examination 2007, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.