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Question Bank No: 1

1. Which of the following solutions when added to 1 L of 0.1 M ${CH}_{3} COOH$ will decrease the pH of the solution

a)		1L of $H_{2} O$
b)		1L of 0.1 M ${CH}_{3} COONa$
c)		1L of 0.1 M HCL
d)		1L of 0.1 M ${CH}_{3} COOH$

2. 100 ml of 0.2 M HCL are mixed with 100ml of 0.2 M ${CH}_{3} COOH,$ the pH of the resulting solution would be nearly

a)		1
b)		0.7
c)		1.3
d)		1.6

3. Equal volumes of two solutions, one having pH 6 and the other having pH 4 are mixed. The pH of the resulting solution would be

a)		5.7
b)		4.3
c)		5.0
d)		5.5

4. When sodium acetate is added to an aqueous solution of acetic acid its pH

a)		Increases
b)		Decreases
c)		Remains constant
d)		may increase or decrease

5. An equimolar solution of ${CH}_{3} COOH$ and ${CH}_{3} COONa$ has pH of 6. The value of Ka for acetic acid is

a)		$10^{6}$
b)		1 $\times 10^{- 6}$
c)		2 ${\times 10}^{- 6}$
d)		cannot be predicted

6. The solubility product, $K_{sp}$ of the sparingly soluble salt A $g_{2} Cr O_{4}$ is 4 $\times 10^{- 12} .$ The solubility of the salt is

a)		1 $\times 10^{- 12} mol L^{- 1}$
b)		2 $\times 10^{- 6} mol L^{- 1}$
c)		$10^{- 6} mol L^{- 1}$
d)		$10^{- 4} mol L^{- 1}$

7. A certain weak acid has a dissociation constant 1.0 $\times 10^{- 4} .$ The equilibrium constant for its reaction with strong base is

a)		1.0 $\times 10^{- 4}$
b)		1.0 $\times 10^{- 10}$
c)		1.0 $\times 10^{10}$
d)		1.0 $\times 10^{- 14}$

8. The pH of 0.005 M aqueous solution of $H_{2} S O_{4}$ is nearly,

a)		0.005
b)		2
c)		1
d)		0.01

9. A 0.20M solution of methanoic acid has degree of dissociation 0.032. Its dissociation constant is

a)		2.1 $\times 10^{- 2}$
b)		9.6 $\times 10^{- 8}$
c)		2.1 $\times 10^{- 4}$
d)		1.1 $\times 10^{- 6}$

10. 200 mL of $\frac{M}{50} HCL$ are mixed with 100 mL of $\frac{M}{100} HCL,$ the pH of the resulting solution would be

a)		2.22
b)		1.78
c)		2
d)		0

11. $K_{sp}$ of a substance XY is $10^{- 2} mo l^{2} L^{- 2} .$ Molecular mass of the substance is 100. Its solubility would be

a)		100 g $L^{- 1}$
b)		1 g $L^{- 1}$
c)		10 g $L^{- 1}$
d)		$10^{- 1}$ g $L^{- 1}$

12. For an elementary reaction, the specific rate constants for forward and reverse reactions are 0.50 and 5 $\times 10^{4}$ respectively. The equilibrium constant for the reaction would be

a)		2.5 $\times 10^{3}$
b)		2.5 $\times 10^{4}$
c)		1 $\times 10^{- 5}$
d)		1 $\times 10^{5}$

13. Vapour density of PC $L_{5}$ is 104.16 but when heated to $230^{0} C$ its vapour density is reduced to 62. The degree of dissociation of PC $L_{5}$ at this temperature will be

a)		6.8%
b)		68%
c)		46%
d)		64%

14. The reagent N $H_{4} CL$ and aqueous N $H_{3}$ will percipitate

a)		C $a^{2 +}$
b)		A $L^{3 +}$
c)		M $g^{2 +}$
d)		Z $n^{2 +}$

15. If $H^{+}$ ion concentration of a solution is increased by 10 times then its pH

a)		Increases by one
b)		remains unchanged
c)		decreases by one
d)		increases by 10

16. Highest pH(14) is given by

a)		0.1 M $H_{2} S O_{4}$
b)		0.1 M NaOH
c)		1N NaOH
d)		1N HCL

17. Amongest the following the weakest base is

a)		potassium hydroxide
b)		sodium hydroxide
c)		magnesium hydroxide
d)		calcium hydroxide

18. The dissociation of water at $25^{0} C$ is 1.9 $\times 10^{- 6}$ percent and the density of water is 1.0g ${cm}^{- 3} .$ The ionisation constant of water is

a)		3.42 $\times 10^{- 6}$
b)		2.00 $\times 10^{- 14}$
c)		3.12 $\times 10^{- 4}$
d)		1.00 $\times 10^{- 14}$

19. In which of the following cases, does the reaction go the farthest for completion?

a)		K= $10^{3}$
b)		K= $10^{- 2}$
c)		K=10
d)		K=1

20. For the gas phase reaction
$N_{2} + 0_{2} ⇌$ 2NO;
$Δ H = + 180 kJ {mol}^{- 1}$
which of the following is true?

a)		The value of K changes with change in pressure
b)		The value of K changes with introduction of NO
c)		The value of K change with change in concentration of $N_{2}$
d)		The value of K change with change in temperature

21. Which of the following statements is correct about the equilibrium constant?

a)		Its value increases by increase in temperature
b)		Its value decreases by decrease in temperature
c)		Its value may increase or decrease with increase in temperature
d)		Its value is constant at all temperatures

22. Consider the two gaseous equilibria involving ${SO}_{2}$ and the corresponding equilibrium constants at 298 K.
${SO}_{2} (g) + \frac{1}{2} O_{2} (g) ⇌$ ${SO}_{3} (g) ... K_{1}$
${2 SO}_{3} (g) ⇌$ ${2 SO}_{2} (g) + O_{2} (g) ... K_{1}$
The values of equilibrium constant are related as:

a)		${2 K}_{1} = {K_{2}}^{2}$
b)		${K_{2}}^{2} \frac{1}{K_{1}}$
c)		${K_{1}}^{2} \frac{1}{K_{2}}$
d)		$K_{2} = \frac{2}{{K_{1}}^{2}}$

23. An aqueous solution of sodium carbonate has a pH greater than 7 because

a)		It contains more carbonate ions than $H_{2} O$ molecules
b)		It contains more sodium ions than $H_{2} O$ molecules
c)		${Na}^{+}$ ions decompose water
d)		Carbonate ions decompose $H_{2} O$

24. Which of the following cannot act as a Lewis acid or Bronsted acid

a)		${BF}_{3}$
b)		${AlCl}_{3}$
c)		${SnCl}_{4}$
d)		${CCl}_{4}$

25. The reagent ${NH}_{4} Cl$ and ${NH}_{3}$ will precipitate

a)		${Ca}^{2 +}$
b)		${Al}^{3 +}$
c)		${Mg}^{2 +}$
d)		${Zn}^{2 +}$

26. The solubility of PbC $l_{2}$ is

a)		$\sqrt{K_{sp}}$
b)		${(K_{sp})}^{\frac{1}{3}}$
c)		${(K_{sp} / 4)}^{\frac{1}{3}}$
d)		${({8 K}_{sp})}^{\frac{1}{2}}$

27. At a certain temp. 2HI $⇌$ $H_{2} + I_{2}$ only 50% HI is dissociated at equilibrium.The equilibrium constant is

a)		0.25
b)		1.0
c)		3.0
d)		0.50

28. The conjugate base in the following reaction
$H_{2} {SO}_{4} + H_{2} O \leftrightarrow H_{3} O^{+} + {HSO}_{4}^{-}$

a)		$H_{2} O$
b)		${HSO}_{4}^{-}$
c)		$H_{3} O$
d)		${SO}_{2}$

29. Which is a buffer solution?

a)		${CH}_{3} COOH + {CH}_{3} COONa$
b)		${CH}_{3} COOH + {CH}_{3} COON H_{4}$
c)		${CH}_{3} COOH + N H_{4} Cl$
d)		NaOH+NaCL

30. The pH of 0.001M solution of HCl is

a)		1.0
b)		3.0
c)		10.0
d)		11.0

31. Amongst the following the weakest base is

a)		potassium hydroxide
b)		sodium hydroxide
c)		magnesium hydroxide
d)		calcium hydroxide

32. The solubility of calcium fluoride is found to be s mol $L^{- 1}$ .The solubility product is

a)		$\sqrt{2}$ s
b)		${2 s}^{2}$
c)		${4 s}^{3}$
d)		2s

33. From the following values of dissolution constants of the acids which value represents the strongest acid?

a)		2 $\times 10^{- 2}$
b)		0.02 $\times 10^{- 1}$
c)		3 $\times 10^{- 3}$
d)		2 $.0 \times 10^{- 4}$

34. In which of the following cases,does the reaction go the farthest for completion?

a)		K= $10^{3}$
b)		K= $10^{- 2}$
c)		K=10
d)		K=1

35. Which of the following has highest ${}_{P}H$ ?

a)		${CH}_{3} COOK$
b)		${Na}_{2} {CO}_{3}$
c)		${NH}_{4} Cl$
d)		Na ${NO}_{3}$

36. Solution of 0.1 N N $H_{4} OH$ and 0.1 N ${NH}_{4} Cl$ has ${}_{p}{H 9.25}$
Then ${{}_{p}K}_{b}$ of ${NH}_{4} OH$ is

a)		9.25
b)		4.75
c)		3.75
d)		8.25

37. The strongest conjugate base is

a)		${NO}_{3}^{-}$
b)		${Cl}^{-}$
c)		${SO}_{4}^{2 -}$
d)		C $H_{3} CO O^{-}$

38. In which of the following gaseous equilibria, the equilibrium will shift to the right if total pressure is increased.

a)		$N_{2} + 3 H_{2} ⇌ 2 {NH}_{3}$
b)		PC $l_{5} ⇌ {PCl}_{3} + C l_{2}$
c)		$H_{2} + {Cl}_{2} ⇌ 2 HCl$
d)		$N_{2} O_{4} ⇌ 2 {NO}_{2}$

39. In which of the following equilibria will $K_{e}$ and $K_{p}$ have the same value?

a)		PC $l_{5} ⇌ {PCl}_{3} + C l_{2}$
b)		$N_{2} + 3 H_{2} ⇌ 2 {NH}_{3}$
c)		2CO + $O_{2} ⇌ {CO}_{2}$
d)		$N_{2} + O_{2} ⇌ 2 NO$

40. For the reaction, C(s) + ${CO}_{2} (g) ⇌ 2 CO (g),$ the partial pressures of ${CO}_{2}$ and CO are 2.0 and 4.0 atm respectively at equilibrium. The $K_{p}$ for the reaction is

a)		2.0 atm
b)		0.5 atm
c)		4.0 atm
d)		8.0 atm

41. A quantity of PC $l_{s}$ was heated in a 10 L vessel at 525 K.
${PCl}_{5} (g) ⇌ PC l_{3} (g) + {Cl}_{2} (g)$
At equilibrium the vessel contains 0.10 mole of PC $l_{5},$ 0.20 mole of PC $l_{3}$ and 0.20 mole of C $l_{2} .$ The equilibrium constant for the reaction is

a)		0.04
b)		0.4
c)		0.02
d)		0.05

42. For the following reaction in gaseous phase CO + $\frac{1}{2}$ $O_{2} ⇌ {CO}_{2}$
$K_{p} / K_{e}$ is

a)		${(RT)}^{1 / 2}$
b)		${(RT)}^{- 1 / 2}$
c)		(RT)
d)		${(RT)}^{- 1}$

43. When equal volume of the following solutions are mixed, precipitation of AgCl( $K_{sp} = 1.8 \times 10^{- 10})$ will occur only with

a)		$10^{- 4} M {A g^{+}}$ and $10^{- 4} M {{Cl}^{-}}$
b)		$10^{- 5} M {A g^{+}}$ and $10^{- 5} M {{Cl}^{-}}$
c)		$10^{- 5} M {A g^{+}}$ and $10^{- 6} M {{Cl}^{-}}$
d)		$10^{- 10} M {A g^{+}}$ and $10^{- 10} M {{Cl}^{-}}$

44. If $H^{+}$ ion concentration of a solution is increased by 10 times then its ${}_{p}H$

a)		increases by one
b)		remains unchanged
c)		decreases by one
d)		increases by 10

45. Highest ${}_{p}H$ (14) is given by

a)		0.1M $H_{2} S O_{4}$
b)		0.1M NaOH
c)		IN NaOH
d)		IN HCl

46. Consider the two gaseous equilibria involving ${SO}_{2}$ and the corresponding equilibrium constant at 298 K.
${SO}_{2} (g) + \frac{1}{2} O_{2} (g) ⇌ {SO}_{3} (g); K_{1}$
2 ${SO}_{3} (g) ⇌ {SO}_{2} (g) + O_{2} (g); K_{2}$

a)		$K_{1} = K_{2}$
b)		$K_{2} = K_{1^{2}}$
c)		$K_{2} = \frac{1}{K_{1^{2}}}$
d)		$K_{2} = \frac{1}{K_{1}}$

47. Asolution was prepared by mixing 50ml of 0.2 M HCl and 50 ml of 0.10 M NaOH. The ${}_{p}H$ of the solution is

a)		7.0
b)		2.0
c)		3.0
d)		1.3

48. For the chemical equilibrium : A(g) + B(g) $⇌_{400^{0} C}^{1 atm}$ C(g) - Qcal

a)		$K_{p} > K_{e}$
b)		$K_{p} = K_{e}$
c)		$K_{p} < K_{e}$
d)		$K_{e}$ is independent of temperature

49. The dissociation of water at $25^{o} C$ is 1.9 $\times 10^{- 6}$ percent and the density of water is 1.0g ${cm}^{- 3} .$ The ionisation constant of water is

a)		3.42 $\times 10^{- 6}$
b)		2.00 $\times 10^{- 14}$
c)		3.42 $\times 10^{- 8}$
d)		1.00 $\times 10^{- 14}$

50. In the reaction ${2 SO}_{2} + O_{2} ⇌ {2 SO}_{3,} K_{e} = 100$ if the concentration of ${SO}_{2}$ is same as that of ${SO}_{3,}$ then

a)		conc.of $O_{2}$ is equal to that of ${SO}_{2}$
b)		[ $O_{2}] = 0.01 M$
c)		conc.of $O_{2}$ is equal to that of ${SO}_{3}$
d)		[ $O_{2}] = 0.1 M$