question paper

1. (a)Correct the following statements.
(i) The melting points of crystalline and amorphous solids are not definite.
The melting point of an amorphous solid is not definite. OR
The melting point of a crystalline solid is definite.
P  Ps
 X solute .
Ps
P  Ps
The equation for relative lowering of vapour pressure when solute remains normal is
 X solute
P
(iii)The degree of ionization decreases with dilution.
The degree of ionisation increases with dilution.
(iv) Tertiary butyl halide and alcoholic potassium hydroxide undergo electrophillic elimination reaction.
Tertiary butyl halide and alcoholic potassium hydroxide undergo nucleophillic elimination reaction.
(v) Silicon carbide is prepared by heating a mixture of sand, coke, saw dust and alkali in an electric furnace.
Silicon carbide is prepared by heating a mixture of sand, coke, sawdust and salt in an electric furnace.
(b) Each question is followed by four possible choices of answers. Choose the correct answer and write it in your answer booklet. (i) The solubility of a gas increases with the increase of
A
volume of the gas.
B concentration.
C
temperature.
D pressure.
(ii) The number of neutrons in a parent nucleus X which gives 7 N 14 nucleus after two successive β-emissions would be
A
6.
B 7.
C
8.
D 9.

(ii) The equation for the relative lowering of vapour pressure when solute remains normal is

(iii)The relative lowering of vapour pressure of a solvent by the addition of a solute is
A
equal to the mole fraction of the solute.
B
equal to the mole fraction of the solvent.
C
directly proportional to the molality of the solution. D directly proportional to the molarity of the solution.
(iv) When primary amines are treated with chloroform and caustic potash in C2H5OH (ethyl alcohol), the product is
A
a secondary amine.
B a nitro compound.
C
an isocyanide.
D a cyanide.
(v) In an adiabatic process, which of the following is true?
A
q=0
B q = +w
C
ΔE = q
D PΔV