Hello Aspirants! In this article, we brought to you the multiple choice questions from class 11 Chemistry chapter 1. These questions will be helpful for your CBSE exam preparations, as well as competitive exams like JEE and NEET. Good Luck. 

For chapter-wise MCQ questions, visit the following links: 

• Biology MCQ Questions
• Chemistry MCQ Questions
• Physics MCQ Questions
• Mathematics MCQ Questions

Questions 1-10

1. The weight of oxygen in one mole each of Fe₂O₃ and FeO is in the simple ratio of:
a) 3 : 2
b) 1 : 2
c) 2 : 1
d) 3 : 1

2. The equivalent weight of a bivalent metal is 37.2. The molecular weight of its chloride is
a) 412.2
b) 216
c) 145.4
d) 108.2

3. 0.0833 moles of carbohydrate of empirical formula CH₂O contains 1 g of hydrogen. The molecular formula of the carbohydrate is
a) C₅H₁₀O₅
b) C₃H₄O₃
c) C₁₂H₂₂O₁₁
d) C₆ H₁₂O₆

4. The equivalent weight of Zn(OH)₂ in the following reaction is equal to its,
Zn(OH)₂ + HNO₃ ⟶ Zn(OH)(NO₃) + H₂O:
a) (Formula wt.)/1
b) (Formula wt.)/2
c) 2 × formula wt.
d) 3 × formula wt.

5. 5.85 g of NaCl are dissolved in 90 g of water. The mole fraction of NaCl is:
a) 0.1
b) 0.01
c) 0.2
d) 0.0196

6. 2.76 g of silver carbonate on being strongly heated yields a residue weighing
a) 2.16 g
b) 2.48 g
c) 2.64 g
d) 2.32 g

7. A solution contains Na₂CO₃ and NaHCO₃. 10 mL of the solution required 2.5 mL of 0.1 M H₂SO₄ for neutralization using phenolphthalein as an indicator. Methyl orange was then added when a further 2.5 mL of 0.2 MH₂SO₄ was required. The amount of Na₂CO₃ in 1 liter of the solution is:
a) 5.3 g and 4.2 g
b) 3.3 g and 6.2 g
c) 4.2 g and 5.3 g
d) 6.2 g and 3.3 g

8. The volume occupied by one molecule of water (density 1 g cm^-3) is:
a) 18 cm³
b) 22400 cm³
c) 6.023×10^-23 cm³
d) 3.0×10^-23 cm³

9. 510 mg of a liquid on vaporization in Victor Meyer’s apparatus displaces 67.2 cm³ of air at (STP). The molecular weight of the liquid is:
a) 130
b) 17
c) 170
d) 1700

10. What volume of 6M HCL should be added to 2M HCL to get 1L of 3M HCL?
a) 0.25 L
b) 1.00 L
c) 0.75 L
d) 2.50 L

Answers

1. d 2. c 3. d 4. a 5. d 6. a 7. a 8. d 9. c 10. a 

Solutions

Questions 11-20

11. The normality of one molar sodium carbonate solution is:
a) 2
b) 1
c) 0.5
d) 1.5

12. If H₂SO₄ ionises as H₂SO₄ + 2 H₂O → 2 H₃O⁺ + SO₄^2-, then total number of ions produced by 0.1M H₂SO₄ will be
a) 9.03×10²¹
b) 3.01×10²²
c) 6.02×10²²
d) 1.8×10²³

13. W₁ of an element combines with oxygen forming W₂ g of its oxide. The equivalent weight of the element is:
a) [W₁ / W₂ ]×8
b) [W₁/(W₂-W₁ )]×8
c) [(W₂-W₁)/W₁ ]×8
d) [W₁/(W₁-W₂ )]×8

14. A sample of ammonium phosphate (NH₄)₃PO₄ contains 6.36 moles of hydrogen atoms. The number of moles of oxygen atom in the sample is (atomic mass of N = 14.04, H = 1, P = 31, O = 16)
a) 0.265
b) 0.795
c) 2.12
d) 4.14

15. To neutralize 20 mL of M/ 10 NaOH, the volume of M/20 HCl needed is:
a) 10 mL
b) 30 mL
c) 40 mL
d) 20 mL

16. A, E, M, and n are the atomic weight, equivalent weight, molecular weight, and valence of an element. The correct relation is:
a) A = E×n
b) A=M/E
c) A=M/n
d) M=A×n

17. Which one of the following sets of units represents the smallest and largest amount of energy respectively?
a) J and erg
b) erg and cal
c) Cal and eV
d) eV and L-atm

18. The number of atoms present in a 0.635 g of Cu piece will be
a) 6.023×10^-23
b) 6.023×10²³
c) 6.023×10²²
d) 6.023×10²¹

19. What volume of hydrogen gas, at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen?
a) 89.6 L
b) 67.2 L
c) 44.8 L
d) 22.4 L

20. The numerical value of N/n (where N is the number of molecules in n moles of gas) is:
a) 8.314
b) 6.02 ×10²³
c) 1.602×10^-24
d) 1.66×10^-19

Answers

11. a 12. d 13. b 14. c 15. c 16. a 17. d 18. d 19. b 20. b 

Solutions

Questions 21-30

21. In the relationship molecular formula = empirical formula × n. The 'n' may have:
a) Any value
b) Zero value
c) Only positive integer value
d) None of the above

22. 10g CaCO₃on heating gives 5.6 g CaO and …. g CO₂.
a) 4.4
b) 5.6
c) 6.5
d) 4.2

23. Which of the following changes with an increase in temperature?
a) Molality
b) Weight fraction of solute
c) Fraction of solute present in water
d) Mole fraction

24. On combustion of 4 g of the methane, 10.46 kJ of heat is liberated. The heat of combustion of methane is
a) 83.68 kJ
b) 10.46 kJ
c) 41.84 kJ
d) 20.93 kJ

25. A gas is found to have the formula (CO)_x. Its VD is 70. The value of x must be:
a) 7
b) 4
c) 5
d) 6

26. Choose the wrong statement.
a) 1 mole means 6.023×10²³ particles
b) Molar mass is the mass of one molecule
c) Molar mass is the mass of one mole of a substance
d) Molar mass is molecular mass expressed in grams

27. The term standard solution is used for the solutions whose:
a) Normality is known
b) Molarity is known
c) Strength is known
d) All of these

28. The ratio of the mole fraction of a solute and a solvent in a binary solution is:
a) Ratio of their wt.
b) One
c) Ratio of their mole
d) Zero

29. If in a reaction HNO₃ is reduced to NO, the mass of HNO₃ absorbing one mole of electrons would be
a) 21.0 g
b) 36.5 g
c) 18.0 g
d) 31.5 g

30. At STP 5.6 litre of a gas weighs 60 g. The vapor density of the gas is:
a) 60
b) 120
c) 30
d) 240

Answers

21. c 22. a 23. c 24. c 25. c 26. b 27. d 28. c 29. a 30. b 

Solutions

Questions 31-40

31. The number of atoms present in 16 g of oxygen gas is:
a) 6.02×10^11.5
b) 3.01×10²³
c) 3.01×10^11.5
d) 6.02×10²³

32. On analysis a certain compound was found to contain iodine and oxygen in the ratio of 254 g of iodine (at. mass 127) and 80 g of oxygen (at. mass 16). What is the formula of the compound?
a) IO
b) I₂ O
c) I₂ O₃
d) I₂ O₅

33. The vapor density of a volatile chloride of a metal is 95 and the specific heat of the metal is 0.13 cal/g. The equivalent weight of the metal will be:
a) 6.0
b) 12.3
c) 18.6
d) 24.5

34. The equivalent weight of a certain trivalent element is 20. The molecular weight of its oxide is
a) 152
b) 56
c) 168
d) 68

35. Gram molecular volume of oxygen at STP is
a) 3200 cm³
b) 5600 cm³
c) 22400 cm³
d) 11200 cm³

36. Two elements X (at. Wt. 75) and Y (at. wt. 16) combine to give a compound having 75.8% ofX. The formula of the compound will be
a) XY
b) X₂ Y
c) XY₃
d) X₂ Y₃

37. The amount of oxalic acid (hydrated) required to prepare 500 mL of its 0.1 N solution is:
a) 0.315 g
b) 6.3 g
c) 3.15 g
d) 63.0 g

38. The equivalent weight of KMnO₄ for an acid solution is
a) 79
b) 52.16
c) 158
d) 31.6

39. Consider a titration of potassium dichromate solution with acidified Mohr’s salt solution using diphenylamine as an indicator. The number of moles of Mohr’s salt required per mole of dichromate is
a) 3
b) 4
c) 5
d) 6

40. A mixture of CH₄,N₂ and O₂ is enclosed in a vessel of one litre capacity at 0°C. The ratio of particle pressures of gases is 1 : 4 : 2. Total pressure of the gaseous mixture is 2660 mm. The number of molecules of oxygen present in the vessel is
a) (6.02×10²³)/22.4
b) 6.02×10²³
c) 22.4×10²²
d) 1000

Answers

31. d 32. d 33. b 34. c 35. b 36. d 37. c 38. d 39. d 40. a 

Solutions

Questions 41-50

41. xg of Ag was dissolved in HNO₃ and the solution was treated with excess NaCl when 2.87 g of AgCl was precipitated. The value of x is
a) 1.08 g
b) 2.16 g
c) 2.70 g
d) 1.62 g

42. One mole electron means:
a) N electrons
b) 6.023 ×10²³electrons
c) 0.55 mg electrons
d) All of these

43. A signature, written in carbon pencil weighs 1 mg. What is the number of carbon atoms present in the signature?
a) 5.02×10²³
b) 5.02×10²⁰
c) 6.02×10²⁰
d) 0.502×10²⁰

44. The minimum quantity of H₂S needed to precipitate 63.5 g of Cu²⁺ will be nearly:
a) 63.5 g
b) 31.75 g
c) 34 g
d) 20 g

45. An unknown element forms an oxide. What will be the equivalent weight of the element if the oxygen content is 20% by weight?
a) 16
b) 32
c) 8
d) 64

46. Cortisone is a molecular substance containing 21 atoms of carbon per molecule. The molecular weight of cortisone is 360.4. what is the percentage of carbon in cortisone?
a) 59.9%
b) 75%
c) 69.98%
d) None of these

47. Which mode of expressing concentration is independent of temperature?
a) Molality
b) Percent by weight
c) Mole fraction
d) All of these

48. An ion is reduced to the element when it absorbs 6×10²⁰ electrons. The number of the equivalent of ion is:
a) 0.1
b) 0.01
c) 0.001
d) 0.0001

49. The volume of 0.1 MH₂ SO₄ required to neutralize 30 mL of 2.0 M NaOH is:
a) 100 mL
b) 300 mL
c) 400 mL
d) 200 mL

50. The law of definite proportions is not applicable to nitrogen oxide because
a) Nitrogen atomic weight is not constant
b) Nitrogen molecular weight is variable
c) Nitrogen equivalent weight is variable
d) Oxygen atomic weight is variable

Answers

Solutions

This is all for this article. Thanks for visiting our website.