Chemistry Ist Year Unit # 2

Distribution law is employed in which of the following
(A) paper chromatography
(B) sublimation
(C) crystillization
(D) solvent extraction

2.when hot saturated solution is cooled rapidly we get
(A) medium sized crystalls
(B) large sized crystals
(C) premature crystillization
(D) no crystallization

3.when I2 is presnent in aqueous layer in form of I3^-1 goes to CCl4 layer then the change in colour is from
(A) purple to brown
(B) purple to green
(C) green to brown
(D) brown to purple

4. The crystallization of a solid substance is done from hot saturated solution. The solution is
(A) evaporated rapidly
(B) cooled slowly to get good crystalls
(C) cooled rapidly to get excellent crystals
(D) mixed with another miscible solvent

5) A sintered glass crucible can be used to :
(A) purify a solid substance
(B) crystallize the solid substance
(C) seperate two miscible liquids
(D) avoid premature crystallization of solute

6. When a solute distributes b/w a stationary phase and a mobile phase the process is called
(A) sublimation
(B) crystallization
(C) solvent extraction
(D) chromatography

7. The iodine present in water can be seperated by which of the following techniques:
(A) sublimation
(B) chromatography
(C) filtration
(D) solvent extraction

8. The process of solvent extraction is an equilibrium process and it obeys
(A) the realtive amounts of solvent and solute
(B) law of mass action
(C) distribution law
(D) all above

9. I2 present in water can be extracted by:
(A) Etanol
(B) acetic acid
(C) chloroform
(D) ccl4

10. Nacl and sand can be seperated by:
(A) formation of solution and filtration
(B) formation of solution and evaporation without filtration
(C) sublimation
(D) chromatograph

11. one of the following substance is used as drying agent in dessicator is
(A) diethyl ether
(B) bleaching powder
(C) silica gel
(D) phosphoric acid

12. which of the following substances used as decoluring agent
(A) animal charcoal
(B) Conc H2so4
(C) Cacl2
(D) silica gel

13 chemical characterization of the substance is
(A) physical chemistry
(B) applied chemistry
(C) analytical chemistry
(D) biochemistry

14. one of the following agent is not used as drying reagent in a dessicator
(A) conc H2SO4
(B) P2O5
(C) silica gel
(D) 50% KOH

15. In order to dry the crystals safely , we should :
(A) place them in an oven
(B) evaporate the solvent at room temperature
(C) warm the substances
(D) press the precipitate between folds of filter paper

16. When repeated extraction are performed by using small quantities of the solvent then this process is more
(A) efficient
(B) rapid
(C) accurate
(D) slow

17. which of the following substances is a sublime material
(A) potash alum
(B) Nacl
(C) Acetic acid
(D) benzoic acid

18. One of the following substance doesnot undergo sublimation
(A) KMNO4
(B) Naphthalene
(C) NH4Cl
(D) Iodine

19. In.paper chromatography the point at which solvent rises to maximum extent is
(A) event
(B) chromayogram
(C) solvent front
(D) baseline

20. The rate at which solute moves in paper chromatography depends upon
(A) distribution coefficeint
(B) distribution law
(C) boiling point if solvent
(D) low partial pressures