Chemistry 1st Year Chapter 9 Solution Notes MCQs Bank

chemistry 11th notes chapter 9

1. A mixture of benzene and toluene form:

 
 
 
 

2. The substances which don’t dissolve in a reasonable amount in a particular solvent are_____.

 
 
 
 

3. Which pair of the following will not form an ideal solution?

 
 
 
 

4. 10g of NaOH has been dissolved per dm³ of solution. The molarity of solution is:

 
 
 
 

5. When the solvent is containing non-volatile solute particles, then:

 
 
 
 

6. The number of molecules of sugar in 1dm³ of 1M sugar solution is:

 
 
 
 

7. A colligative property is not represented by:

 
 
 
 

8. Which of the following is affected by temperature change:

 
 
 
 

9. Molal boiling point constant is the ratio of the elevation in the boiling to:

 
 
 
 

10. 10g NaOH is dissolved in 1000g water. The molality of NaOH is:

 
 
 
 

11. 250cm³ of 0.2 molar potassium sulphate solution is mixed with 250cm³ of 0.2 molar KCl solution. The molar concentration of K⁺ ions is:

 
 
 
 

12. The sum of mole fraction of all the components of solution is always equal to:

 
 
 
 

13. Which of the following is an example of solid in solid solution?

 
 
 
 

14. Which of the following statement is true about ideal solutions?

 
 
 
 

15. A solution of KCl in water contains:

 
 
 
 

16. The molarity of 2 percent W/v NaOH solution is:

 
 
 
 

17. An aqueous solution boil at 100.52°C. It should freeze at:

 
 
 
 

18. The relative lowering of vapor pressure is equal to:

 
 
 
 

19. If 9.8g H₂SO₄ is present in one dm³ of solution, the solution is:

 
 
 
 

20. Which one of the following solution of glucose in water is more dilute?

 
 
 
 

21. A solution of glucose is 10% w/v. The volume in which 1g mole of it is dissolved will be:

 
 
 
 

22. Which of the following liquid pairs will obey the Raoult’s law:

 
 
 
 

23. 10 percent aqueous solution of glucose freezes at:

 
 
 
 

24. Which of the following 0.1 m solution will have the lowest freezing point?

 
 
 
 

25. Which has maximum freezing point:

 
 
 
 

26. The study of elevation of boiling point is called:

 
 
 
 

27. That solution which possesses a maximum concentration of solute at a given temperature is known as:

 
 
 
 

28. In a solution 7.8g benzene and 46g toluene (C₆H₅CH₃) is present, the mole fraction of benzene is:

 
 
 
 

29. Which pair of mixture is called ideal solution:

 
 
 
 

30. A solution has 92g ethanol, 96g methanol, and 90g water. Mole fraction of water in the solution is:

 
 
 
 

31. Which has the highest freezing point?

 
 
 
 

32. Which liquid solute is dissolved in the liquid solvent, then the best unit of concentration is?

 
 
 
 

33. The freezing point is the temperature of the substance at which its solid and liquid phases have the:

 
 
 
 

34. Which cation has least heat of hydration:

 
 
 
 

35. Which of the following concentration unit is used for very dilute solutions:

 
 
 
 

36. Colligative properties can be used for calculating:

 
 
 
 

37. 15g urea is dissolved in 180 cm3 of water. The relative lowering of vapour pressure will be:

 
 
 
 

38. Hydrolysis of CH₃COOK will produce:

 
 
 
 

39. Elevation of boiling point can be best studied by:

 
 
 
 

40. Which of the following is not a colligative property?

 
 
 
 

41. Which one of the following salts do not hydrolyse:

 
 
 
 

42. For observing Colligative properties, which of the following conditions should be fulfilled?

 
 
 
 

43. For very dilute solution the following expression is used:

 
 
 
 

44. 18 g glucose is dissolved in 90g of water. The relative lowering of vapour pressure is equal to:

 
 
 
 

45. The molality of pure water is:

 
 
 
 

46. The addition of sodium chloride to water, while boiling eggs results to:

 
 
 
 

47. The substance which has water of crystallization in it, is called:

 
 
 
 

Short Questions

1. Boiling points of solvents increase due to the presence of solutes. Why?
2. Colligatave properties are obeyed when the solute is non- electrolyte and also when the solutions are dilute?
3. Colligative properties are obeyed when solutions are dilute. Why?
4. Define colligative properties? Name some important colligative properties?
5. Explain why CuSO₄ and NH₄Cl give acid solution when put separately in water?
6. Give two substance of Raoult’s law?
7. H₂O shows discontinuous solubility curve, when plotted against temperature. Why?
8. Heat of solution of a substance is measured at infinite dilution. Why?
9. How does an increase in temperature may increase or decrease the solubility of a substance?
10. How does fractional crystallization help in removing the impurities from a solid substance?
11. How the forces of attractions between the ions and the solvent molecules depend upon the charge densities of the ions?
12. How the ions are stabilized when a strong electrolyte like NaCl and KCl are dissolved in H₂O?
13. How the relative lowering of vapour pressure can help us to calculate the molar mass of a non- volatile, non- electrolyte solute?
14. How will you prepare 5% w/v urea solution in water?
15. If an electrolyte is dissolved in a solvent, the abnormal colligative properties are observed. Why?
16. In summer the antifreeze solutions protect the radiator from boiling over, why?
17. In weight %, we know the masses of solute and solvent but in weight % age, we don’t know the mass of solvent and that of the solution. Give comments?
18. Non- ideal solutions do not obey the Raoult’s law. Why?
19. One molal of solution of urea in water in dilute as compared to one molar solution of urea but the number of particles of the solute is same. Justify it?
20. Prove that the collgative properties like ΔTb and ΔTf are inversely proportional to the molar masses of the solute?
21. The concentration in terms of modality is independent of temperature but morality depends upon the temperature. How?
22. The lowering of vapour pressure, elevation of boiling point and this depression of freezing points are call collligative properties. Comment upon it?
23. The sum of the mole fractions of all the components is always equal to unity for any solution?
24. What are hydrates? How they are formed? Give some examples.
25. What are mathematical formulas of molarity and molality?
26. What do you mean by discontinuous solubility curves?
27. What do you mean by minimum boiling point mixture?
28. What is conjugate solution?
29. What is consulate temperature or critical solution temperature?
30. What is cryoscopic constant?
31. What is ebullioscopic constant?
32. What is effect of temperature on the conjugate solution of water and phenol?
33. What is negative deviation from Raoult’s law?
34. What is positive deviation from Raoult’s law?
35. When heat of solution is negative, then increase in temperature decreases the solubility and vice versa. Why?
36. When we plot a graph between temperature and compositions of binary liquid mixture, straight line is not obtained. We get two curves even for ideal solutions. Justify it?
37. Why a non- volatile solute in a volatile solvent lowers the vapour pressure of solution?
38. Why a salt produced from a weak acid and a strong base gives a basic aqueous solution like CH₃COONa?
39. Why Beckmann thermometer is used to not the depression of freezing point?
40. Why glucose is not soluble in CCl₄, but dissolves in water?
41. Why is salt produced from a strong acid and a strong base is not hydrolysed in water?
42. Why the boiling point of a solution of a non- volatile solute in a volatile solvent is always greater than the boiling point of a pour solvent?
43. Why the freezing point of the solution is always less than the freezing point of the pour solvent?
44. Why the freezing points are depressed due presence of solutes?
45. Why the NaCl and KNO₃ are used to lower the melting point of ice?
46. Why the relative lowering of vapour pressure is independent of temperature?

Long Questions

“1. Define the following terms with examples.
(i) Molarity (ii) Molality (iii) Mole Fraction (iv) Parts per million”
2. Discus the measurement of mass of solute by Beckmann’s method.
3. What is boiling point elevation? Describe a method to determine the boiling point elevation of a solution.
4. Explain the difference between ideal and non-ideal solution.
5. Discuss Raoult’s law for the solution in which both component are volatile.
6. What are colligative properties? Why are they called so?
7. Define non-ideal solutions and explain positive deviation with the help of graph.
8. Define hydrolysis. Why the aqueous solution of NH₄Cl is acidic but that of CH₃COONa is basic.
9. Define Raoult’s law and derive the equation ∆P = P⁰X₂
10. What is Raoult’s law? Give its three statements. How this law can help us to understand the ideality of a solution?
11. What are azeotropic mixtures? Explain them with the help of graph.
12. What is Raoult’s law? Give its three statements.
13. What do you mean by depression of freezing point of a solvent by a solute? Derive molecular mass of a compound by it.
14. The boiling point of water is 99.725 ⁰C. To a sample of 600 gram of water are added 24 gram of a solute having molecular mass of 58 g mole⁻¹ , to form as solution. Calculate the boiling point of the solution
15. The freezing point of Camphor is 178.4 ⁰C. Find the freezing point of a solution containing 2.0 g of non-volatile compound, having molecular mass 140 in 40 g of camphor. The molal freezing point constant of Camphor is 37.7 ᵒC kg mol-
16. Discuss Raoult’s law for the solution in which both components are volatile.
17. Define elevation in boiling point. Explain this with the help of graph.
“18. Define the following terms.
(i) % w/w (ii) ppm (iii) molality (iv) zeotropic mixture”
19. The boiling point of a solution containing 0.2 g of a substance ‘A’ in 20 g of ether is 0.17 k higher than that of pure ether. Calculate the moler mass of ‘A’. Bolling point constant of ether is 2.16 K
20. Discuss the measurement of mass of solute by Beckmann’s method.
21. What are partially miscible liquids? Describe phenol-water system
22. Differentiate between hydration and hydrolysis.
“23. (b) Explain why?
Aqueous solution of Al₂(SO₄)₃ is acidic. (ii)Aqueous solution of Na₂CO₃ is alkaline.”
24. What is hydration energy? On what factors does it depend? Give example
25. What are colligative properties. Why are these called colligative? Explain
26. You are provided with 80% sulphuric acid having density 1.8 gcm⁻³, How much volume of this sulphuric acid sample is required to obtain 1 dm of 20% H₂SO₄ whose density is 1.25 g/dm³

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