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CBSE Important Questions

CBSE Guess > Papers > Important Questions > Class XII > 2013 > Chemistry > Solutions By Mr. R. Srinivas Vasudevamurthy

CBSE CLASS XII

Solutions - 5 Marks Questions

1. Define the following terms:

a) molarity
b) molality
c) mole fraction
d) mass%
e) volume %
f) parts per million
g) azeotrope.

2. What is the effect of temperature on the molarity of the solution ?

3. molality, mole fraction, and mass% are independent of temperature. Why?

4. What is the effect of temperature on the solubility of

a) solid in a liquid
b) gas in a liquid ?

5. State Henry’s law. Give the mathematical expression for the law.

6. Mention three applications of Henry’s law.

7. State Raoult’s law for a solution containing two volatile solvents. Give the mathematical expression for the law.

8. Derive the mathematical expression to show that the relative lowering of vapor
   pressure of a solution containing a nonvolatile solute and a volatile solvent  is equal to
  the mole fraction of the solute.

9. Mention the condition where Raoult’s law becomes a special case of Henry’s law.

10. What are ideal solutions? Mention the conditions for a solution to behave ideally.Draw a graph of vapor pressure vs mole fraction for an ideal solution.

11. What are non ideal solutions? Mention the conditions for a solution to behave non ideally.

12. Explain the type of deviation exhibited by a mixture of

a) ethanol and acetone
b) acetone and chloroform.
c) phenol and aniline. Draw a graph of vapor pressure vs mole fraction in each case.

13. What do you mean by the terms

a) maximum boiling azeotrope
b) minimum boiling azeotrope. Give one example each.

14. What are colligative properties? Give four examples.

15. Explain the following colligative properties with suitable graphs.

a) elevation of boiling point
b) depression of freezing point.

16. Define Kf and Kb. Give mathematical expression to show that Kf and Kb depends on the nature of the solvent.

17. Define osmosis and osmotic pressure. Why is osmotic pressure method is considered as a better method when compared to other colligative properties to determine molar mass of the solute.

18. What is reverse osmosis? Mention one application of the same.

19. What do you mean by abnormal molar mass? How does it occur due to

a) association of solute?
b) dissociation of solute?

20. What is Van’t Hoff factor i? Give its value for

a) association of solute.
b) dissociation of solute.
c) solute which is neither associates nor dissociates

21. Which is more concentrated? 1 molar or 1 molal solution. Why?

22. What do you mean by the terms

a) isotonic solution.
b) hypertonic solution
c) hypotonic solution?

23. Account for the following:

a) intravenous injection is given by using 0.9% NaCl (mass/volume) solution.
b) Dried fruits and vegetables swell when kept in fresh water.
c) The tanks used by scuba divers are diluted with helium.
d) Mountain climbers sometimes get symptoms of a condition known as anoxia.
e) Calcium chloride is added to clear the roads covered by snow.
f) Raw mango placed in concentrated salt solution shrivel in to pickle.
g) People suffering from high blood pressure are advised to take minimum quantity of salty food.
h) People taking lot of salty food get affected by edema.
i) Meat is preserved by salting and fruits are preserved by adding sugar.

24. What will happen when a blood cell is placed in

a) solution having NaCl concentration less than 0.9%(mass/volume)
b) solution having NaCl concentration higher than 0.9%(mass/volume)?

      

Submitted By : Mr. R. Srinivas Vasudevamurthy
Email: vasudm@yahoo.co.uk