(b) ethane
(c) ethylene
(d) acetylene
Ans: (d)
190. The gas used in the weldings of the metallic joints is :
(a) ethylene
(b) acetylene
(c) propylene
(d) methane
Ans: (b)
191. Which one among the following is a source of methane emission into the atmosphere?
(a) Automobile exhaust fume
(b) Industrial chimney
(c) Mining
(d) Wetland
Ans: (d)
192. The toxic gas lewisite used in the war is prepared by :
(a) chlorine
(b) ammonia
(c) acetylene
(d) nitrobenzene
Ans: (c)
193. The element which has maximum number of isotopes is :
(a) Bismuth
(b) Nickel
(c) Lead
(d) Polonium
Ans: (d)
194. Which of the following chemically predominants in the silk fibres? [CDS 2010]
(a) Protein
(b) Carbohydrate
(c) Complex lipid
(d) Mixture of polysaccharide and fat
Ans: (b)
195. The chloroform is kept in the coloured bottle (container) because it directly reacts with air and light and forms a
toxic substance which is:
(a) phosphin
(b) phosgene
(c) mustard gas
(d) CO
Ans: (b)
196. The carbon tetrachloride is also known as :
(a) marsh gas
(b) mustard gas
(c) pyrin
(d) pyrole
Ans: (c)
197. The fire extinguisher used in the electric firing is:
(a) pyrin extinguisher
(b) foam (leather) extinguisher
(c) water extinguisher
(d) soda acid extinguisher
Ans: (a)
198. Which of the following is also known as wood spirit:
(a) methyl alcohol
(b) ethyl alcohol
(c) ethylene glycol
(d) glycerol
Ans: (a)
199. The antifreezer is a mixture of :
(a) acetic acid and water
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