Lessons :9,10,11,12
1MARKS
CHEMISTRY
1X15=15
1. When a liquid boils, there is
a) an increase in entropy b) a decrease in entropy
c) an increase in heat of vapourisation d) an increase in free energy
5. All the naturally occuring processes proceed spontaneously in a direction
which leads to
a) decrease of entropy b) increase in enthalpy
c) increase in free energy d) decrease of free energy
6. Which of the following does not result in an increase in the entropy?
a) crystallisation of sucrose from solution b) rusting of iron
c) conversion of ice to water d) vaporisation of camphor
7. State of chemical equilibrium is:
a) dynamic b) stationery c) none d) both
8. Hydrolysis of an ester by dilute HCl is an example for
(a) second order reaction (b) zero order reaction
(c) pseudo first order reaction (d) first order reaction
9. The unit of zero order rate constant is
(a) litre mol–1 sec–1 (b) mol litre–1 sec–1
(c) sec–1 (d) litre2 sec–1
10. The excess energy which a molecule must posses to become active is
known as
(a) kinetic energy (b) threshold energy
(c) potential energy (d) activation energy
11. Arrhenius equation is
(a) k = Ae–1/RT (b) k = Ae–RT/Ea (c) k = Ae–Ea/RT (d) k = AeEa/RT
75 MARKS
12. The term A in Arrhenius equation is called as
(a) Probability factor (b) Activation of energy
(c) Collision factor (d) Frequency factor
13. The migration of colloidal particles under the influence of an electric
field is known as
(a) electroosmosis (b) cataphoresis
(c) electrodialysis (d) electrophoresis
14. Which one is the correct factor that explains the increase of rate of reaction
by a catalyst
(a) shape selectivity (b) particle size
(c) increase of free energy (d) lowering of activation energy
15. Fog is a colloidal solution of
(a) gas in liquid (b) liquid in gas
(c) gas in solid (d) solid in gas.
3 Marks.
10X3=30
1.What is entropy?What are the units of entropy?
2.What is Gibb’s free energy?
3.Give Kelvin statement of second law of thermodynamics.
4. Evaluate the entropy change for the following process possessing H
transition = 2090 J.mol-1
5.Degree of dissociation of PCl5 at 1 atm and 25C is 0.2. Calculate the
pressure at which PCl5 is half dissociated at 25C.
6..Define reaction quotient.
7.What is activation energy?
8.What is pseudo first order reaction?
9.What is consecutive reaction ? Give an examples.
10.What is electrophoresis?
11.Colloidal system of gas in gas does not exist.Why?
12.what are promoters?Give examples.
5 Marks.
3X5=15
1.Explain the ultra filtration process.
2. A certain amount of methyl acetate was hydrolysed in the
presence of excess of 0.05 M HCl at 25°C. 20 mL of reaction mixture were
removed and titrated with NaOH solution, the volume V of alkali required
for neutralisation after time ‘t’ were as follows :
t (min) 0
20
40
60

v (mL) 20.2 25.6 29.5 32.8 50.4
3.Explain the Characteristics of entropy ‘S’.
4. Initially, 0.1 moles each of H2 and I2 gases and 0.02 moles of HI gas
are mixed in a reaction vessel of constant volume at 300K. Predict the direction
towards which the reaction proceeds [Kc = 3.5 × 10-2].
10Marks
3X5=15
1.Explain the applications of colloid chemistry are limitless. These can be divided
mainly into two classes:
1. Natural applications and
2. Technical applications
2.
a) The activation energy of a certain reaction is 100 KJ/mole
what is the change in the rate constant of the reaction if the temperature is
changed from 25°C to 35°C ? Let the rate constants at 25°C be k1 and at
35°C be k2 respectively.
b) Explain the Characteristics of Free energy ‘G’.