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:
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+ + SO42-, 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) 6.02×1011.5
b) 3.01×1023
c) 3.01×1011.5
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
41. b 42. d 43. d 44. c 45. b 46. c 47. d 48. c 49. b 50. c
Solutions
This is all for this article. Thanks for visiting our website.