40.   The oxidation state of oxygen in OF2 is: [CDS 2000]
         (a) +2
         (b) -2
         (c) +1
         (d) -1
Ans: (a)
41. The acid is a substance which:
         (a) accepts (gains) electron
         (b) donates electron
         (c) provides (donates) proton
         (d) donates OH- ion
Ans: (c)
42. Which acid substance is found in vinegar? [MPPCS (Pre) 2011]
         (a) Lactic Acid
         (b) Citric Acid
         (c) Maleic Acid
         (d) Acetic Acid
Ans: (d)
43. Which one of the following compounds is used as freezerd medicine? [UPPCS (Pre) 2010]
         (a) KBr
         (b) CaCl2
         (c) C2H5OH
         (d) PCl3
Ans: (a)
44. The solution of Hypo which is frequently utilized in the photography is an aqueous solution of-[UPPCS (Pre) 2010]
         (a) Sodium thiosulphate
         (b) Sodium tetra thionate
         (c) Sodium sulphate
         (d) Ammonium persulphate
Ans: (a)
45. Which one of the following heaviest element is of nickel group? [RRB TC 2009]
         (a) Platinum
         (b) Radium
         (c) Plodium
         (d) Iron
Ans: (a)
46. Iron nails are dipped into blue copper sulphate solution. After some time iron nails are- [NDA 2011]
         (a) dissolved and blue colour is discharged
         (b) dissolved but blue colour is not discharged
         (c) not dissolved and blue colour is not discharged
         (d) not dissolved but blue colour is discharged
Ans: (a)
47. The average pH value of the milk is:
         (a) 6.1
         (b) 6.6
         (c) 7.4
         (d) 8
Ans: (b)
48. Mohr salt is a
         (a) simple salt
         (b) hybrid salt
         (c) double salt
         (d) complex salt
Ans: (c)
49. A student by chance mixed acetone with alcohol. This mixture of acetone and alcohol can be separated by-
         [NDA2011]
         (a) Filtration
         (b) Separating funnel
         (c) Fractional crystalization
         (d) Fractional distillation
Ans: (d)
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