(b) Wohler
     (c) Baeyer
     (d) Perkin
Ans: (a)
249. The rate of setting of cement is slowed down by the addition of
     (a) quicklime
     (b) gypsum
     (c) soda lime
     (d) bleaching powder
Ans: (b)
250. Nylon is made from
     (a) terephthalic acid and ethylene glycol
     (b) hexamethylene diamine and adipic acid
     (c) cellulose nitrate
     (d) cellulose acetate
Ans: (b)
251. An example of thermo setting plastics is
     (a) bakelite
     (b) polythene
     (c) PVC
     (d) Teflon
Ans: (a)
252. A valuable by-product in the manufacture of soap is
     (a) stearic acid
     (b) sodium hydroxide
     (c) palmitic acid
     (d) glycerol
Ans: (d)
253. The name rubber was given by
     (a) Lavoisier
     (b) Priestley
     (c) Dalton
     (d) Avogadro
Ans: (b)
254. The soaps used in shaving cream are
     (a) calcium soaps
     (b) lead soaps
     (c) soft soaps
     (d) hard soaps
Ans: (c)
255. Lead soaps are used in
     (a) shaving creams
     (b) adhesive tapes
     (c) toilet powders
     (d) lubricants
Ans: (b)
256. Grape sugar is another name for