(d) 1, 3 and 4
Ans: (c)
99. An acid used to remove inkspots is:
     (a) oxalic acid
     (b) butyric acid
     (c) lactic acid
     (d) tartaric acid
Ans: (a)
100. Two solutions are isotonic when they:
     (a) are of the same concentration
     (b) have the same osmotic pressure
     (c) have the same number of isotopes
     (d) have the same substance saturating them
Ans: (b)
101. Tile noble gases do not react with any other atom because:
     (a) they are heavy elements
     (b) they are stable compounds
     (c) their outermost orbits contain eight electrons
     (d) None of the above
Ans: (c)
102. Dialysis is used for people with defective kidneys, It involves the process of:
     (a) adsorption
     (b) osmosis
     (c) electropheresis
     (d) diffusion
Ans: (b)
103. Which of the following compounds are responsible for "acid rain" ?
          1) Nitrogen dioxide
          2) Silicon dioxide
          3) Sulphur dioxide
          4) Carbon monoxide
     (a) 1 and 2
     (b) 1 and 3
     (c) 2 and 4
     (d) 3 and 4
Ans: (b)
104. The substance coated on plastic tape-recorder tapes is :
     (a) zinc oxide
     (b) manganse oxide
     (c) iron sulphate
     (d) iron oxide
Ans: (d)
105. In addition to the idea that matter consists of molecules, the kinetic theory of matter assumes that these molecules:
     (a) are perfectly stationary in solids