(a)   formic acid
         (b)   oxallic acid
         (c)   citric acid
         (d)   acetic acid
Ans: (b)
220. Itching due to insect bite is caused by- [CDS 2010]
         (a) Formic acid
         (b) Acetic acid
         (c) Lactic acid
         (d) Maleic acid
Ans: (b)
221. Which of the following is chemical formula of urea:
         (a) NH4Cl
         (b) NH2CONH4
         (c) NH2CONH2
         (d) NH3
Ans: (c)
222. In urea, nitrogen is to be found in the form of :
         (a) nitrate
         (b) nitrite
         (c) ammonium
         (d) amide
Ans: (d)
223. The percentage amount of nitrogen present in urea is :
         (a) 26%
         (b) 36%
         (c) 46%
         (d) 60%
Ans: (c)
224. The first synthesis of urea in the laboratory was done by :
         (a) Williamson
         (b) Kolbe
         (c) Wohler
         (d) Bertholet
Ans: (c)
225. A woman intends a chemical wash of her ornaments without any quantity loss, then which of the following
         chemicals will be suitable for the wash? [NDA 2010]
         (a) aquaregia
         (b) conc H2SO4
         (c) conc NaOH
         (d) solution of NaS2O7
Ans: (d)
226. Which of the following is used in Dry Cleaning:
         (a) benzene
         (b) nitrobenzene
         (c) chlorobenzene
         (d) hydroxic benzene
Ans: (a)
227. Which of the following is obtained by the reaction of benzene and chlorine in the presence of a catalyst? [CDS
         (a) benzene hexachloride
         (b) benzyle chloride
         (c) chloro benzene
         (d) benzoyl chloride
Ans: (c)
228. Trinitro Toluene (TNT) is a / an :
         (a) pesticide
         (b) insecticide
         (c) explosive
         (d) germicide
Ans: (c)