148. Copper is purified by
     (a) poling
     (b) tempering
     (c) calcination
     (d) galvanising
Ans: (a)
149. Cinnabar is an ore of
     (a) lead
     (b) zinc
     (c) mercury
     (d) chromium
Ans: (c)
150. Brass contains
     (a) copper and tin
     (b) aluminium and magnesium
     (c) copper and zinc
     (d) copper, tin and zinc
Ans: (c)
151. Metals are usually heavy. A light metal is
     (a) manganese
     (b) copper
     (c) potassium
     (d) plumbum
Ans: (c)
152. A metal which is extracted by thermal reduction is
     (a) nickel
     (b) aluminium
     (c) mercury
     (d) calcium
Ans: (c)
153. White lead is
     (a) a basic salt
     (b) an acid salt
     (c) a double salt
     (d) a normal salt
Ans: (a)
154. An acid which is used as a preservative for pickles is
     (a) hydrochloric acid
     (b) citric acid
     (c) tartaric acid
     (d) acetic acid
Ans: (d)
155. A metal which occurs "free" in nature is
     (a) gold
     (b) zinc
     (c) tin
     (d) molybdenum
Ans: (a)