FSC 1st Year Chemistry 2nd Chapter MCQs

Chapter 2: Experimental techniques in chemistry

In this article, the author has explained the most important chemistry MCQs from the second chapter( Experimental techniques in chemistry) of FSC chemistry. All the correct answers have been highlighted in blue color.

1: Which separation technique is best for purifying a liquid that contains some undissolved solids?

a) Sublimation

b) Chromatography

c) Filtration

d) Crystallization

2: The filtration of mixtures containing oxidizing agents can be easily done by using

a) A filter paper

b) A sintered glass crucible

c) A simple Gooch crucible

d) All of these

3: How would you separate NaCl from sand?

a) Formation of the solution, filtration followed by evaporation

b) Formation of solution, filtration followed by crystallization

c) Filtration followed by sublimation

d) Solvent extraction

4: Which of the following is not a feature of crystallizing solvents?

a) It should be chemically inert

b) It should be easily removeable

c) It should be expensive

d) It should be safe to use

5: How could a mixture of two liquid compounds, one red and the other blue be separated?

a) By sublimation

b) By chromatography

c) By crystallization

d) None of these

6: A hot saturated solution of white crystalline compounds was allowed to cool slowly, what wpould you observe?

a) Nothing happens

b) Large white crystals are formed

c) White fine crystals are fromed

d) None of these

7: Which of the followings cannot be used as drying agent in desiccators?

a) NaCl

b) CaCl₂

c) P₂O₅

d) Silica gel

8: The best method for separating ammonium chloride from calcium chloride is

a) Chromatography

b) Sublimation

c) Solvent extraction

d) None of these

9: Solvent extraction cannot be used for the separation of a mixture of

a) NaCl and CuSO₄

b) Petrol and n-butanol

c) Benzene and glucose

d) None of these

10: In ether extraction, ether layer is

a) At the top

b) In between two layers of water

c) At the bottom

d) None of these

11: CuCl₂is a blue crystalline salt, it will be soluble in

a) Ether

b) Acetone

c) Water

d) Ethylacetate

12: The stationary phase of chromatography is

a) A solid always

b) A solid or liquid

c) A liquid only

d) A solid or liquid or a gas

13: Which of the followings is not true for the mobile phase in chromatography?

a) It can never be solid

b) It can be gas

c) It can never be liquid or a gas

d) None of these

14: In absorption chromatography, the stationary phase is a

a) Solid

b) Liquid

c) Solid or liquid

d) None of these

15: The chromatography in which the stationary phase is liquid is called

a) Column chromatography

b) Adsorption chromatography

c) Partition chromatography

d) All of these

16: Paper chromatography is a type of

a) Partition chromatography

b) Adsorption chromatography

c) Thin layer chromatography

d) None of these

17: What would be the best fro separating benzoic acid containing a small impurity of iodine?

a) Sublimation

b) Solvent Extraction

c) Chromatography

d) Crystallization

18: All of the following mixtures can be separated into their components by sublimation except

a) Benzoic acid + Phenol

b) Iodine + NaCl

c) Benzoic acid + Iodine

d) NH₄Cl + CaCl₂

19: Which of the following pairs can be used for solvent extraction?

a) Benzene and Toluene

b) Alcohol and water

c) Xylene and Benzene

d) Water and ethylacetate

20: Solvent extraction can be used for the separation of the component of mixture of

a) Two ionic solids

^{b) One polar and one non polar solid}

c) Two compounds of same polarity

d) None of these

21: Two of the components of a complex mixture of compounds, having more affinity for the mobile phase would have R_fvalues

a) 0.5

b) less than 0.5

c) more than 0.5

d) none of these

22: All of the following are wrong except;

a) Only solids can be purified by solvent extraction

b) Chromatography can only be used for the separation of components of colored mixtures

c) Crystallization can be used to purify iodine

d) Vacuum desiccation is preferred for drying hygroscopic compounds

23: All of the followings are correct except;

a) Only one crystallization is enough for purification always

b) Rapid cooling of a saturated solution of sugar in an organic solvent in a refrigerator produces small sized crystals

c) Solvent extraction is not always used for the separation of solid mixtures

d) None of the common separation techniques can be used for the separation of isotopes of an element

24: Which of the followings cannot be used for the separation of two isomorphic crystalline compounds?

a) Solvent extraction

b) Chromatography

c) Crystallization in a single solvent

d) None of these

25: Which of the following solvents will form a lower layer in a separatory funnel when used in connection with water?

a) Methanol

b) Ethanol

c) Diethyl ether

d) Chloroform

26: All of the following can be separated by solvent extraction but

a) Naphthalene from benzoic acid

b) Sodium acetate from ethyl acetate

c) Stearic acid from palmitic acid

d) All of these

27: Rate of filtration can be increased by using a

a) Fluted filter paper

b) Large Gooch crucible

c) Suction pump

d) All of these

28: When I₂present in the aqueous layer in the form of I₃^1-goes to CCl₄layer, then the change in colour is from

a) Purple to brown

b) Green to brown

c) Purple to green

d) Brown to purple

29: The rate of filtration in using fluted paper is greater as compared to simply solded filter paper due to the reason that

a) It has greater surface of the paper

b) It is more absorbent

c) It has greater size of pores

d) All of these

30: Which of the following would lose weight when exposed to the open environment?

a) A concentrated H₂SO₄ solution

b) A saturated solution of CO₂

c) Solid NaOH

d) Anhydrous Na₂CO₃

31: Gooch crucible is used when

a) Quick filtration is to be done

b) The residue has to be ignited at high temperature

c) A suction pump is to be employed

d) All of the above are true

32: Chromatography cannot be used for the separation of

a) Two liquid compounds

b) Two aqueous substances

c) More than three covalent compounds

d) All of these

33: A solvent used for crystallization should dissolve;

a) Maximum solute at room temperature

b) Maximum solute at its boiling point

c) Minimum solute at room temperature

d) None

34: if none of the solvent is found suitable for crystallization;

a) A mixture of two miscible solvents is used

b) A mixture of two immiscible solvents is used

c) A mixture of organic and inorganic solvents is used

d) None of the above

35: In solvent extraction a solute distributes itself between two immiscible solvents in a constant ratio of concentrations

a) Depending upon the amount of solvent added

b) Depending upon the amount of solute added

c) Independent of the amount of solvent added

d) Independent of the amount of solute added

36: During the process of filtration, the hot saturated solution is _____ to get crystals

a) Cooled very slowly

b) Evaporated

c) Cooled at moderate rate

d) Mixed with immiscible liquid

37: Sublimation is used when the product to be separated is

a) Volatile and thermally stable

b) Non-volatile and themally stable

c) Non-volatile and themally unstable

d) Volatile and themally unstable

38: The comparative rates at which solutes move in paper chromatography depend on:

a) Size of paper

b) Temperature of experiment

c) Retardation factor of solutes

d) Size of chromatographic tank used

39: Aspirin is insoluble in water; it will be separated from it by;

a) Sublimation

b) Chromatography

c) Solvent Extraction

d) Filtration

40: A crude product is crystallized to;

a) Characterize it

b) Determine no. of elements

c) Purify it

d) None