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Entry Test Preparation 2015, Chemistry BOOK 1 Chapter # 9 Solutions , MCQS with Answer Keys

Entry Test Preparation 2015, Chemistry BOOK 1 Chapter # 9 Solutions , MCQS with Answer Keys

zohaib hassan 9:18 PM Add Comment

Entry Test Preparation 2015

Chemistry

CHAPTER NO 9
SOLUTIONS

1. The molarity of solution containing 1.5g urea dissolved in 100 cm³ of the solution is.

(a) 1 molar (b) 0.1 molar (c) 0.2 molar (d) 0.25 molar

2. The molarity of glucose solution is 0.02, the mass of glucose in 50 cm³ of the solution is.

(a) 1.8g (b) 0.18g (c) 2.18g (d) 18g

3. The molarity of solution containing 103g (NH₄)₂SO₄ in 600 cm³ of the solution.

(a) 1.32 (b) 1.45 (c) 1.62 (d) 1.65

4. K₂CO₃ is dissolved in water, the solution is 0,1 molar. The mass of the it in 250 cm of solution is.

(a) 2gm (b) 3gm (c) 3.45gm (d) 4 gm

5. The molarity of toluene solution in benzene is 0.22 if 5 g of toluene is dissolved, then the mass of benzene in grams.

(a) 267 (b) 260 (c) 240 (d) 247

6. 0.1 molar glucose solution has % W/ V

(a) 1.8% (b) 18% (c) 2.8% (d) 2.8%

7. 10% aqueous solution of NaCl has molarity.

(a) 1.7 M (b) 2.7M (c) 0.17M (d) 3.7M

8. 50 cm³ of 0.05 molar urea solution has % W/V concentration.

(a) 6% (b) 18% (c) 0.18% (d) 2.8%

9. Which one of the following solution will have higher vapour pressure than that of water.

(a) Aqueous solution of Methanol (b) Aqueous solution of HCl

(c) Aqueous solution of glucose (d) Aqueous solution of urea

10. Which one of the following is used as antifreeze in the radiator.

(a) Methanol (b) Ethanol (c) Ethylene glycol (d) Glycerin

11. Which of the following salts mixed with ice to make the freezing mixture used in the ice-cream machine.

(a) KNO₃ (b) NH₄NO₃ (c) AgNO₃ (d) Mg(NO₃)₂

12. The order of salvation i.e. hydration energy of LiCl, MgCl₂, CuCl₂ and NH₄Cl is.

(a) LiCl>MgCl₂>CuCl₂>NH₄Cl (b) NH₄Cl>CuCl₂>LiCl>MgCl₂

(c) CuCl₂>NH₄Cl>MgCl₂>LiCl (d) MgCl₂>CuCl₂>LiCl>NH₄Cl

13. Which one of the following aqueous solution is acidic.

(a) CH₃COONa (b) NaCl (c) AlCl₃ (d) Na₂CO₃

14. Which one of the following aqueous solution is basic.

(a) NaCl (b) NaNO₃ (c) AlCl₃ (d) Na₂CO₃

15. 12g urea or 36 g glucose when dissolved in 1000g water increase the boiling point of water to 100.104^oC. for an identical solution the amount of sucrose required is.

(a) 34.2g (b) 68.4g (c) 342g (d) 3.42

16. 1 Kg of sea water contains 4.96 x 10^-3 g of dissolved oxygen. The concentration of oxygen in sea water in parts per million is:

(a) 4.96 x 10^-2 (b) 0.496 (c) 4.96 (d) 49.6

17. 36% W/V solution of HCl has the molarity.

(a) 1.0 (b) 1.15 (c) 0.98 (d) 1.98

18. The freezing mixture used in ice cream machine consist of ice and

(a) KNO₃ (b) KCl (c) MgCl₂ (d) NaNO₃

19. 17.1 g sucrose dissolved in 250 cm³ of solution. This has % W/V and molarity.

(a) 10%, 0.1 M (b) 6.84%, 0.2 M (c) 1%, 0.01 M (d) 4.84%, 0.1 M

20. 5% (W/W) aqueous sugar solution has its molarity.

(a) 0.15 (b) 0.05 (c) 0.2 (d) 0.25

21. 10% (W/W) aqueous NaCl solution has its% (W/V)

(a) 10% (b) 11% (c) 11.11% (d) 10.11%

22. 10 g naphthalene is dissolved in 200 g benzene, then molarity of solution is.

(a) 0.5 (b) 0.05 (c) 0.29 (d) 0.39

23. A Solution consisting of 92 g ethyl alcohol (C₂II₅OII) 96 g methyl alcohol (CH₃OH) 90 g water the mole fraction and mole percent of methyl alcohol is.

(a) 0.3, 30% (b) 0.2, 30% (c) 0.5, 30% (d) 0.2, 20%

24. A solution containing 5,8 g acetone, 4.6 g ethyl alcohol and 12 g chloroform has mole fraction and mole percent of acetone.

(a) 0.11, 10% (b) 0.33, 33% (c) 0.22,22% (d) 0.11, 33%

25. The number of moles of NH₄Cl dissolved in 500 cm³ of its 15% W/V solution is.

(a) 1 mole (b) 1.4 moles (c) 2.0 moles (d) 2.4 moles

26. Silver amalgam is a solution consisting of the type.

(a) Liquid is solute and solvent is solid. (b) Liquid is solute, liquid is solvent

(c) Solid is solute and solid is the solvent (d) Gas is solute and solid is solvent

27. Ethylene glycol is mixed with water as antifreeze in radiator because.

(a) It has low vapour pressure (b) It lower the freezing point of water

(c) It raises the boiling point of water (d) It has all the above characters.

28. Which of the following solutions will have different composition of liquid and vapour phases at their boiling points.

(a) Ethanol + Water (b0 Benzene + Toluene

(c) Acetone + Chloroform (d) Water + HCl

29. Aqueous solution of methanol is zeotropic mixture because.

(a) It does not obey Rault’s law.

(b) Mixture cannot be separated by fractional distillation

(c) Solution of non-volatile, strong electrolyte

(d) Mixture can be separated by fractional distillation

30. Which of the following half molar solutions will have lowest freezing point.

(a) Solution of non-volatile, non electrolyte

(b) Solution of non-volatile, weak electrolyte.

(c) Solution of non-volatile, strong electrolyte.

(d) Solution of volatile, non-electrolyte

31. A solution of 0.5 mole camphor in 100 g chloroform (Kb = 0.322) has rise in boiling point than that of chloroform.

(a) 0.81^oC (b) 1.61^oC (c) 1.81^oC (d) 0.61^oC

32. Dust particles in smoke is a solution of type.

(a) Liquid is solute and solid is solvent. (b) Solid is solute and liquid is solvent.

(c) Solid is solute and gas is solvent. (d) Gas is solute and solid is solvent

33. Which of the following is a solution of solid is solute and solid is the solvent.

(a) Butter (b) Mercury in silver (c) Smoke (d) Steel

34. Which of the following is not an example of the solution of liquid is solute and gas is the solvent.

(a) Aerated water (b) Clouds (c) Fog (d) Liquid air pollutant s

35. Cane sugar is not soluble in benzene but soluble in water because.

(a) Cane sugar is a macro molecule (b) Cane sugar is an ionic compound

(c) Cane sugar has hydrogen bonding (d) Cane sugar is an organic molecule

36. Which one of the following is not soluble in acetone.

(a) NaCl (b) Urea (c) Cane Sugar (d) Alcohol

37. When equal volumes of ether and water are shaken, then two layers are formed, the ether’ layer contains water.

(a) 2.1% (b) 1.2% (c) 5.6% (d) 6.5%

38. When equal volumes of phenol and water are mixed together at 25^oC, the upper layer has the phenol water percentage.

(a) 5% phenol + 95% water (b) 10% phenol + 90% water

(c) 15% phenol + 85 water (d) 8.5 phenol + 66% water

39. The critical solution temperature of phenol in water solution is 65.9 ^oC. At this temperature the phenol water percentage is.

(a) 50% phenol + 50% water (b) 66% phenol + 34% water

(c) 30% phenol + 70% water (d) 34% phenol + 66% water

40. Vapour pressure of pure water is 28.4 torr. Cane sugar is dissolved in it which lowers the vapour pressure of solution to 25 torr. The mole fraction of cane sugar is.

(a) 0.48 (b) 0.24 (c) 0.12 (d) 0.02

41. Vapour pressure of pure water is 35 torr. 30g urea is dissolved in 81 g water. The vapour pressure of solution becomes.

(a) 30 torr (b) 31.5 torr (c) 31 torr (d) 30.5 torr

42. Which one has the highest heat of hydration

(a)Li⁺² (b)Ag⁺ (c)Mg⁺² (d)Cu⁺²

43. Which one of the following is an ideal solution obeys Rault’s law.

(a) Ethanol + water (b) Benzene + Toluene

(c) HCl+ Water (d) Acetone + Chloroform

44. Which one of the following is non-ideal solution.

(a)Methanol + CCl₄ (b) Benzene + Toluene

(c) HCl + water (d) Acetone + Chloroform

45. Which one of the following mixtures shows positive deviation from Rault’s law and forms an Azeotrope with minimum boiling point.

(a) Ethanol + H₂O (b) Methanol + Acetone

(c) Ether + HCl (d) Acetone + Chloroform

46. Which one of the following mixture exhibits negative deviations from Rault’s law and is an azeotropic mixture with maximum boiling point.

(a) Acetone + CS₂ (b) Methonal + Benzene

(c) Ethanol + Benzene (d) Water + HCl

47. Which statement is incorrect for an ideal solution.

(a) The forces of attractions between solute and solvent molecules are same.

(b) There is no evolution or absorption of heat i.e. AH = 0 on mixing components.

(c) Volume of the solution is less than sum of volumes of individual components.

(d) Vapour pressure of solution is directly proportional to the mole fraction of solvent

48. Which one of the following is not a conjugate solution.

(a) Ether + Water (b) Phenol + Water (c) Nicotine + Water (d) Ethanol + Water

49. The volume of the solution is slightly greater than the sum of individual volumes of the components then this solution is.

(a) An azeotropic mixture showing negative deviation from Rault’s law.

(b) An azeotropic mixture showing positive deviation from Rault’s law.

(c) Ideal solution that obeys Rault’s law.

(d) Super Saturated solution.

50. The vapour pressure of a pure liquid is 60 torr. At 25^oC. The vapour pressure of solution if 3 moles of this substance are mixed with 2 moles of a non-volatile non-electrolyte is.

(a) 48 torr (b) 40 torr (c) 36 torr (d) 30 torr

ANSWERS

(solutions)

1	B	2	C	3	C
4	B	5	A	6	A
7	D	8	B	9	C
10	C	11	B	12	A
13	D	14	A	15	D
16	B	17	A	18	A
19	C	20	D	21	A
22	B	23	C	24	B
25	A	26	D	27	D
28	A	29	D	30	A
31	A	32	C	33	B
34	C	35	B	36	A
37	A	38	B	39	A
40	C	41	B	42	B
43	C	44	A	45	C
46	B	47	B	48	C
49	D	50	D

Entry Test Preparation 2015, Chemistry BOOK 1 Chapter # 10 ELECTROCHEMISTRY, MCQS with Answer Keys

Entry Test Preparation 2015, Chemistry BOOK 1 Chapter # 10 ELECTROCHEMISTRY, MCQS with Answer Keys

zohaib hassan 10:48 PM Add Comment

Entry Test Preparation 2015

ChemistryChapter # 10
ELECTROCHEMISTRY

Direction

You are given following questions from the topic, with four choices A through D. Select the choice that will answer the question best.

1. A solution of sodium sulphate was electrolysed using some inert electrodes. The products at the electrodes are

A. O₂, H₂ B. O₂, Na

C. O₂, SO₂ D. O₂, S2O₈^2-

2. Coinage metals are reactive:

A. least B. most

C. moderate D. none of these

3. Out of Cu, Ag, Fe and Zn the metal which can displace all other from their salt solutions is

A. Ag B. Cu

C. Zn D. Fe

4. The conductivity of strong electrolyte

A. Increases on dilution slightly

B. Does not change on dilution

C. Decreases on dilution

D. Depends on density of electrolyte it self

5. For 12 V in lead accumulator ____cells are connected.

A. 2 B. 6

C. 9 D. 2

6. Which of the following is the use of electrolysis?

A. Extraction of metals B. Electroplating

C. Both A and B D. None of the above

7. Which is the strongest reducing agent:

A. Zn_(s)B. Cr_(s)

C. H_2(g)D. Fe³⁺_(aq)

8. Cr is placed above hydrogen in electrochemical series it has_____ reduction potential than hydrogen.

A. higher B. lower

C. equel D. none

9. Which is the strong oxidizing agent in F2,Cl2,Br2

A. F2 B. Cl2

C. Br2 D. all are equal

10. In fuel cell ____react in presence of KOH.

A. ZnO,MnO2 B. CuSO₄, KCl

C. HgCl₂ D. H_2,O₂

11. Standard reduction electrode potential of three metals A, B and C are erespectively +0.05 V, -3.0V and -1.2V. The reducing power of

A. B > C > A B. A > B > C

C. C > B > A D. A > C > B

12. Conductivity is due to flow of electrons in:

A. Ionic solids B. Covalent solids

C. Metallic solids D. Molecular solids

13. If the salt bridge is not used between two half cells then voltage

A. decreases rapidly B. decreases slowly

C. does not change D. drops to zero

14. Fuel cell is used in

A. B. 550 cm³

C. 5.6 cm³ D. 11.2 cm³

15. Which of the following is non rechargeable battery

A. NICAD B. Alkaline battery

C. Fuel cell D. none

16. Using inert electrodes like Pt or graphite the electrolysis of aqueous sodium chloride produces at chatode

A. Cl₂ gas B. H₂ gas

C. O₂ gas D. HCl gas

17. In the presence of copper electrodes the electrolysis of aqueous CuSO₄ produces at cathode

A. H₂ gas B. O₂ gas

C. SO₂ gas D. Cu metal

18. The cathodic reaction in the electrolysis of dil. H₂SO₄ with Pt electrodes

A. reduction

B. oxidation

C. both oxidation and reduction

D. neither oxidation or reduction

19. Passage of electric current through the metals is due to

A. oxidation reaction B. reduction reaction

C. electrolysis D. free movement of electrons

20. In the electrolysis of aqueous solution of sodium nitrate, the ions which are reduced at the cathode are

A. H₃O⁺ B. Na⁺

C. OH^- D. NO^3-

21. A standard hydrogen electrode is used as standard electrode of which electrode potential is arbitrarily taken as

A. +1 B. -1

C. 0.1 D. zero

22. The reduction potential of copper electrode is +0.34 V and that of Zn electrode is -0.76 V. When these two are coupled the e.m.f. of the cell is

A. -0.42 V B. +0.42

C. -1.10 V D. +1.10 V

23. A dry alkaline cell has porous Zn anode and MnO2 as cathode the electrolyte used is

A. Ca(OH)₂ B. NaOH

C. KOH D. NH₄OH

24. In electronic watches or electronic calculator the tiny batteries used are

A. Alkaline battery B. NICAD battery

C. Fuel cell D. Silver oxide battery

25. Silver oxide battery has a voltage of

A. 2.0 V B. 1.5 V

C. 2.5 V D. 1.0 V

26. Which statement is incorrect for NICAD battery

A. The electrolyte is alkali B. Cd acts as anode

C. MnO₂ acts as electrolyte D. NiO₂ acts as cathode

27. The oxidation number of H is – 1 in the compound

A. H₂O B. H₃BO₃

C. NaOH D. NaH

28. In F₂O the oxidation state of oxygen is

A. -2 B. -1

C. +1 D. +2

29. The oxidation number of Mn in KMnO₄ is

A. +2 B. +4

C. +6 D. +7

30. The oxidation state of Cr in K₂Cr₂O₇ is

A. +3 B. +6

C. +9 D. +4

31. An oxidizing agent in a chemical reaction is the substance which

A. loses electrons B. gains electrons

C. pH is changed D. acts as a catalyst

32. In the reaction

Cu + HNO₃

Cu(NO₃)₂ + NO + H₂O the atom which is oxidized

A. Cu B. H

C. N D. O

33. In KO₂the oxidation state of oxygen is

A. -2 B. -1

C. +1/2 D. -1/2

34. Standard reduction potential of F is the highest in the electrochemical series which is

A. +4.87 B. +3.87

C. +2.87 D. +1.87

35. Fe can displace Cu form CuSO₄ solution

A. Fe is ferromagnetic

B. Fe is below Cu in electrochemical series

C. Fe is above Cu in electrochemical series

D. Fe exist in divalent oxidation sate

36. Which of the following reaction does not involve either oxidation or reduction?

A. VO^-2

V₂O₃ B. Na

Na⁺

C. CrO₄^-2

Cr₂O₇^-2 D. Zn^-2

Zn

37. In the reaction, MnO₄^- + 5Fe²⁺ + 8H⁺

Mn²⁺ + 5Fe³⁺ + 4H₂O, the oxidation

number of Manganese:

A. increases from – 1 to +2 B. decreases from +7 to +2

C. increases from +3 to +5 D. remains unchanged

38. The potential difference responsible for the flow of current from the electrode of higher potential to one of lower potential is called:

A. electrolysis B. electromotive force

C. resistance D. electrolytic conduction

39. “The current strength flowing through a conductor at uniform temperature is proportional to the potential difference at the end of the conductor and is inversely proportional to the resistance”. This is the statement of:

A. Faraday law B. Law of themodynamics

C. Ohm’s law D. Raoult’s law

40. In a cell containing Zinc electrode & normal hydrogen electrode, the Zinc electrode acts as:

A. Cathode B. Anode

C. Reducing electrode D. None of the above

41. The e.m.f. of Galvanic cell of the reaction is:

Zn

Zn^-2 + 2e^- (E^o = -0.76 V)

Cu⁺² + 2e

Cu (E^o = +0.34 V)

A. -0.42V B. -0.10

C. +1.10V D. +0.42V

42. The best conductor of electricity is 1M solution of:

A. CH₃COOH B. H₂SO₄

C. H₃PO₄ D. H₃BO₃

43. The equation, NaCl

Na + Cl represents:

A. Electrolysis B. Hydration

C. Theory of ionization D. Common ion effect

44. Which one of the following salts will hydrolyse in water to give basic solution

A. NaCl B. NH₄Cl

C. KCl D. Na₂SO₄

45. The standard reduction potential at 298K for the following half reaction are given against each?

Zn²⁺ + 2e^-

Zn_(s) ; -0.762v

Cr²⁺ + 2e^-

Cr_(s) ; -0.740v

2H⁺ + 2e^-

H2_(g) ; -0.000v

Fe³⁺_(aq) + 3e^-

Fe_(aq) ; -0.770v

46. The standard reduction potential for Fe²⁺ |Fe & Sn²⁺| Sn electrodes are -0.44v & 0.14V respectively. For the cell reaction:

Fe²⁺ +Sn

Fe + Sn²⁺

A. +0.30V B. -0.58V

C. +0.58V D. -0.30V

47. The most common oxidation state of an element is -2. The number of electrons in its outer most shell is:

A. 2 B. 4

C. 6 D. 8

48. The degree of dissociation of an electrolyte does not depends on:

A. nature of electrolyte B. dilution

C. catalytic action D. temperature

49. The degree of dissociation of an electrolyte increases as:

A. dilution increases B. dilution decreases

C. pressure decreases D. low degree of ionization

50. An indicator that changes colour from red to yellow in the presence of an alkaline solution is called:

A. Methyl orange B. Litmus paper

C. Phenolpthalein D. Methyl red

ANSWERS

(electrochemistry)

1	A	2	A	3	C
4	A	5	B	6	C
7	A	8	B	9	A
10	D	11	A	12	C
13	D	14	D	15	B
16	B	17	D	18	A
19	D	20	A	21	D
22	D	23	C	24	D
25	B	26	C	27	D
28	D	29	D	30	B
31	B	32	A	33	D
34	C	35	C	36	C
37	B	38	B	39	C
40	B	41	C	42	B
43	C	44	B	45	A
46	D	47	C	48	C
49	A	50	A

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