1. Which of the following is the example of crystallisation process?
a) Purification of alum
b) Purification of sea water
c) Separation of gases from air
d) None of the mentioned
Explanation: An impure sample of alum or copper sulphate is purified by crystallisation process. Purification of sea water is example of distillation process.
2. At room temperature, the impure compound in crystallisation is ____________
a) Soluble
b) Sparingly soluble
c) Insoluble
d) None of the mentioned
Explanation: The impure compound is sparingly soluble in a solvent at room temperature but appreciably soluble at higher temperatures.
3. Which of the following is known as mother liquor?
a) Solvent
b) Solute
c) Solution
d) Filtrate
Explanation: The filtrate is also known as mother liquor. A mother liquor is the part of a solution that is left over after crystallization. It is encountered in chemical processes including sugar refining.
4. The solution of impure compound and solvent is concentrated to get ____________
a) Unsaturated solution
b) Undersaturaed solution
c) Saturated solution
d) Oversaturated solution
Explanation: The solution of impure compound and solvent is concentrated to get a saturated solution. The solution is filtered to remove insoluble impurities.
5. Insoluble impurities from solution during crystallization are removed by ____________
a) Drying
b) Filtration
c) Heating
d) Cooling
Explanation: Insoluble impurities from solution during crystallization are removed by filtration. The solution is filtered to remove insoluble impurities.
6. The solution which is obtained after filtration is ____________
a) Suspended solution
b) Clear solution
c) Colloidal solution
d) None of the mentioned
Explanation: The solution which is obtained after filtration is a clear solution. The solution is filtered to remove insoluble impurities.
7. Crystal phases can be inter-converted by varying ____________
a) Temperature
b) Pressure
c) Size
d) Viscosity
Explanation: Crystal phases can be inter-converted by varying factors such as temperature.
8. The nature of the crystallization process is governed by _____________
a) Thermodynamics
b) Kinetic factors
c) Thermodynamics and Kinetic factors
d) None of the mentioned
Explanation: The nature of the crystallization process is governed by both thermodynamic and kinetic factors.
9. The unit of surface tension in the CGS system is ____________
a) N/m
b) Kg/cm
c) Dynes/cm
d) Dynes/m
Explanation: The unit of surface tension in CGS system is dynes/cm. It is N/m in S.I. system. Surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible.
10. The apparatus used for the determination of surface tension of a liquid is ____________
a) Oedometer
b) Stalagmometer
c) Consolidometer
d) None of the mentioned
Explanation: The apparatus used for the determination of surface tension of a liquid is called stalagmometer. It is equivalent to force per unit length.