140. Which or the following is not a constituent or gun powder?
(a) Ammonium nitrate
(b) Nitre
(c) Charcoal powder
(d) Sulphur
Ans: (a)
141. A non-metal which is a good conductor or heat and electricity is
(a) iodine
(b) sulphur
(c) graphite
(d) phosphorus
Ans: (c)
142. The earliest known acid is
(a) nitric acid
(b) oxalic acid
(c) carbonic acid
(d) acetic acid
Ans: (d)
143. The pH or pure water is nearly 7.0 It will increase on the addition or
(a) hydrochloric acid
(b) ammonia
(c) cane sugar
(d) common salt
Ans: (b)
144. Which or the following electrolysis?
(a) Aluminium
(b) Copper
(c) Zinc
(d) Iron
Ans: (a)
145. Cupellation is used in the purification of
(a) Lead
(b) Tin
(c) Silver
(d) Gold
Ans: (c)
146. Iron is coated with zinc to prevent rusting. The process is called
(a) annealing
(b) tempering
(c) calcining
(d) galvanising
Ans: (d)
147. Which one of the following metals is used to extract another metal?
(a) Lead
(b) Tin
(c) Zinc
(d) Aluminium
Ans: (d)
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