Q.22 The major constituent of air is
(A) nitrogen
(B) carbon dioxide
(C) oxygen
(D) hydrogen
Q.23 The main chemical constituent of clay is
(A) silicon oxide
(B) aluminium borosilicate
(C) zeolites
(D) aluminium silicate
Q.24 The mineral containing both magnesium and calcium is
(A) magnesite
(B) calcite
(C) carnallite
(D) dolomite
Q.25 The method that cannot be used for removing the permanent hardness of water is
(A) adding sodium carbonate
(B) distillation
(C) adding caustic soda
(D) boiling
Q.26 The following are the half-lives of four active isotopes. Which one of the following is the most dangerous to handle?
(A) 3 billion years
(B) 100 years
(C) 0.01 minute
(D) 13 days
Q.27 The gas used for artificial ripening of green fruit is
(A) ethylene
(B) ethane
(C) carbon dioxide
(D) acetylene
Q.28 Zone refining is used for the purification of
(A) Au
(B) Ge
(C) Ag
(D) Cu
If you have any problem or doubt regarding Chemistry Questions and Answers for Competitive Exams, you can ask me in the comment section. To more practice for General Science Questions, Visit the next page.
Get the Examsbook Prep App Today