Multiple Choice Questions on Mole Concept

 

1. Which of the following is the correct definition of a mole?

a) The number of atoms in 1 gram of an element

b) The number of molecules in 1 gram of a compound

c) The number of particles (atoms, molecules, or ions) in 1 mole of a substance

d) The number of grams of a substance in 1 mole

2. What is the Avogadro's number?

a) The number of atoms in 1 mole of an element

b) The number of molecules in 1 mole of a compound

c) The number of particles (atoms, molecules, or ions) in 1 mole of a substance

d) The number of grams of a substance in 1 mole

3. How many moles of water are in 1 liter of water?

a) 1 mole b) 18 moles c) 55.5 moles d) 6.02 x 10²³ moles

4. What is the molar mass of carbon dioxide (CO2)?

a) 12 g/mol b) 22 g/mol c) 44 g/mol d) 72 g/mol

5. How many grams of hydrogen are in 2 moles of H2O?

a) 2 g b) 4 g c) 8 g d) 16 g

6. What is the mole fraction of ethanol (C2H5OH) in a solution containing 25% ethanol by mass and 75% water?

a) 0.25 b) 0.5 c) 0.75 d) 0.9

7. What is the percentage composition by mass of nitrogen (N) in ammonium nitrate (NH4NO3)?

a) 14% b) 28% c) 35% d) 50%

8. How many moles of oxygen are in 2 moles of Fe2O3?

a) 2 moles b) 3 moles c) 4 moles d) 6 moles

9. What is the molarity of a solution that contains 5 moles of NaCl in 2 liters of solution?

a) 2.5 M b) 5 M c) 7.5 M d) 10 M

10. What is the mass of 2 moles of sulfuric acid (H2SO4)?

a) 49 g b) 98 g c) 196 g d) 392 g

11. What is Avogadro's number?

a) 6.022 x 10²³ b) 6.023 x 10²² c) 6.022 x 10²² d) 6.023 x 10²³

12. What is the mass of one mole of carbon-12 atoms?

a) 12 grams b) 6.022 x 10²³ grams c) 6.022 x 10²³ amu d) 6.022 x 10²³ electrons

13. What is the molar mass of water (H₂O)?

a) 18 g/mol b) 20 g/mol c) 22 g/mol d) 24 g/mol

14. How many moles of oxygen atoms are in 2 moles of CO₂?

a) 2 moles b) 3 moles c) 4 moles d) 6 moles

15. What is the percentage by mass of oxygen in Al₂(SO₄)₃?

a) 16% b) 24% c) 32% d) 48%

16. How many atoms are present in 2 moles of sodium?

A) 6.02 x 10²³ atoms B) 1.20 x 10²⁴ atoms C) 3.01 x 10²⁴ atoms D) 4.81 x 10²⁴ atoms

17. What is the mass of 2 moles of carbon dioxide (CO₂)?

A) 22 grams B) 44 grams C) 66 grams D) 88 grams

18. What is the number of moles present in 25 grams of water (H₂O)?

A) 0.69 moles B) 1.38 moles C) 2.76 moles D) 5.52 moles

19. What is the percentage composition of carbon in methane (CH₄)?

A) 25% B) 50% C) 75% D) 100%

20. What is the molar mass of sodium chloride (NaCl)?

A) 22.99 g/mol B) 35.45 g/mol C) 58.44 g/mol D) 95.89 g/mol

21. The mole is a unit of measurement used in chemistry to represent:

a) Mass b) Volume c) Amount of substance d) Temperature

22. One mole of any gas at standard temperature and pressure (STP) occupies a volume of:

a) 22.4 liters b) 24 liters c) 1 litre d) 1 gallon

23. The Avogadro constant is defined as:

a) The number of atoms in 12 grams of carbon-12

b) The number of molecules in 1 mole of a substance

c) The number of protons in 1 mole of hydrogen atoms

d) The number of neutrons in 1 mole of helium atoms

24. The molar mass of a substance is defined as:

a) The mass of 1 mole of the substance

b) The volume of 1 mole of the substance

c) The temperature of 1 mole of the substance

d) The pressure of 1 mole of the substance

25. The empirical formula of a compound:

a) Gives the actual number of atoms of each element in a molecule

b) Gives the simplest whole-number ratio of the atoms in a molecule

c) Gives the molecular formula of a compound

d) Gives the mass of 1 mole of a compound

26. The molecular formula of a compound:

a) Gives the empirical formula of a compound

b) Gives the simplest whole-number ratio of the atoms in a molecule

c) Gives the actual number of atoms of each element in a molecule

d) Gives the mass of 1 mole of a compound

27. If the molecular formula of a compound is C₆H₁₂O₆, what is the empirical formula?

a) CH₂O b) C₂H₄O₂ c) C₃H₆O₃ d) C₄H₈O₄

28. What is the mass of one mole of water (H₂O)?

a) 18 g b) 32 g c) 22.4 g d) 6.02 x 10²³ g

29. The percent composition of a compound:

a) Gives the molecular formula of a compound

b) Gives the empirical formula of a compound

c) Gives the mass percent of each element in a compound

d) Gives the number of atoms in a compound

30. How many moles of CO₂ are produced when 2 moles of C₂H₅OH react with excess oxygen according to the following equation?

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O

a) 2 moles b) 4 moles c) 6 moles d) 8 moles

31. Which of the following is the correct definition of a mole?

a) A small, furry animal that lives underground b) A unit of measurement used to count particles c) A type of sauce used in Mexican cuisine d) A unit of measurement used to measure distance

32. What is Avogadro's number?

a) The number of particles in one mole of a substance

b) The number of particles in one liter of a gas at STP

c) The number of particles in one gram of a substance

d) The number of particles in one cubic centimeter of a liquid

33. What is the molar mass of water (H₂O)?

a) 18 g/mol b) 22 g/mol c) 24 g/mol d) 26 g/mol

34. How many moles of carbon dioxide (CO₂) are in 44 grams of CO₂?

a) 1 mole b) 2 moles c) 3 moles d) 4 moles

35. How many atoms are in 2 moles of carbon (C)?

a) 6.02 x 10²³ atoms b) 12.04 x 10²³ atoms c) 24.08 x 10²³ atoms d) 48.16 x 10²³ atoms

36. What is the mass of 1 mole of oxygen gas (O₂)?

a) 16 g b) 22.4 g c) 32 g d) 44.8 g

37. How many grams of potassium chloride (KCl) are in 2 moles of KCl?

a) 74 g b) 148 g c) 296 g d) 592 g

38. What is the molar mass of sodium hydroxide (NaOH)?

a) 23 g/mol b) 40 g/mol c) 56 g/mol d) 40 g/mol

39. What is the mass of 1 mole of methane (CH₄)?

a) 16 g b) 28 g c) 32 g d) 36 g

40. What is the percent composition of carbon in carbon dioxide (CO₂)?

a) 27.3% b) 50% c) 72.7% d) 100%

41. What is the Avogadro's constant?

a) 6.022 x 10²³ b) 6.022 x 10^-23 c) 6.022 x 10²⁴ d) 6.022 x 10^-24

42. What is the mass of one mole of oxygen atoms?

a) 16 g b) 32 g c) 48 g d) 64 g

43. What is the molar mass of water?

a) 18 g/mol b) 22.4 g/mol c) 24 g/mol d) 36 g/mol

44. What is the mole fraction of nitrogen in air if the partial pressure of nitrogen is 0.8 atm and the total pressure of air is 1 atm?

a) 0.2 b) 0.4 c) 0.6 d) 0.8

45. What is the concentration of a solution that contains 2 moles of solute in 500 mL of solution?

a) 0.04 M b) 0.2 M c) 4 M d) 20 M

46. What is the definition of a mole?

A. The number of atoms in 12 grams of carbon-12.

B. The number of atoms in 1 gram of hydrogen.

C. The number of particles in 1 mole of a substance.

D. The mass of 1 mole of a substance.

47. How many moles are there in 72 grams of carbon dioxide (CO₂)?

A. 1 mole B. 2 moles C. 3 moles D. 4 moles

48. What is the percentage composition of oxygen in water (H₂O)?

A. 88.89% B. 11.11% C. 66.67% D. 33.33%

49. How many atoms are there in 2 moles of carbon (C)?

A. 6.022 × 10²³ B. 1.2044 × 10²⁴ C. 4.815 × 10²⁴ D. 1.204 × 10²³

50. What is the empirical formula of a compound that contains 54.45% carbon, 9.09% hydrogen, and 36.36% oxygen?

A. CH₂O B. C₂H₄O₂ C. C₆H₁₂O₆ D. C₃H₆O₃

ANSWERS:

 

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

 

 

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