Questions on Conversions Between Moles and Atoms
Multiple-Choice Questions: Conversions Between Moles and Atoms
1. How many atoms are in 1 mole of a substance?
A) 3.01 × 10²³
B) 1.00 × 10²⁴
C) 6.02 × 10²³
D) 1.00 × 10²²
E) 6.02 × 10²⁶
2. How many atoms are in 2 moles of magnesium (Mg)?
A) 6.02 × 10²³
B) 1.20 × 10²⁴
C) 3.01 × 10²³
D) 2.00 × 10²³
E) 1.00 × 10²⁵
3. 0.5 moles of helium contain how many atoms?
A) 3.01 × 10²³
B) 1.20 × 10²⁴
C) 6.02 × 10²³
D) 2.50 × 10²⁴
E) 5.00 × 10²²
4. How many moles are in 3.01 × 10²³ atoms of hydrogen?
A) 0.25 mol
B) 0.50 mol
C) 1 mol
D) 2 mol
E) 1.5 mol
5. You have 1.806 × 10²⁴ atoms of iron (Fe). How many moles is this?
A) 1 mol
B) 2 mol
C) 3 mol
D) 4 mol
E) 5 mol
6. How many atoms are in 0.75 mol of aluminum?
A) 4.52 × 10²³
B) 3.01 × 10²³
C) 6.02 × 10²³
D) 1.20 × 10²⁴
E) 7.52 × 10²³
7. Which of the following contains the greatest number of atoms?
A) 0.5 mol H
B) 1 mol O
C) 2 mol He
D) 1.5 mol Li
E) All contain the same number of atoms per mole
8. How many moles are in 6.02 × 10²² atoms of lithium?
A) 0.1 mol
B) 0.01 mol
C) 0.001 mol
D) 0.5 mol
E) 1 mol
9. You are given 4.00 moles of carbon atoms. How many atoms do you have?
A) 2.41 × 10²⁴
B) 1.50 × 10²⁴
C) 6.02 × 10²³
D) 2.00 × 10²⁴
E) 4.00 × 10²³
10. How many atoms are in 1.5 mol of zinc (Zn)?
A) 9.03 × 10²³
B) 3.01 × 10²³
C) 1.20 × 10²⁴
D) 2.50 × 10²⁴
E) 1.00 × 10²⁴
11. How many moles are in 1.505 × 10²⁴ atoms of gold (Au)?
A) 2.0 mol
B) 1.5 mol
C) 0.5 mol
D) 1.0 mol
E) 2.5 mol
12. Which of the following represents the correct conversion factor for moles to atoms?
A) 6.02 × 10²²
B) 1 mol / 6.02 × 10²³ atoms
C) 6.02 × 10²³ atoms / 1 mol
D) 1 atom / 6.02 × 10²³ mol
E) 1 mol × 6.02
13. You have 2.5 mol of neon atoms. How many atoms is that?
A) 1.51 × 10²³
B) 1.20 × 10²³
C) 3.01 × 10²⁴
D) 2.50 × 10²³
E) 1.51 × 10²⁴
14. How many moles are there in 1.204 × 10²⁴ atoms of sodium?
A) 0.5 mol
B) 1 mol
C) 2 mol
D) 1.5 mol
E) 3 mol
15. If you have 7.53 × 10²³ atoms of potassium, how many moles do you have?
A) 1.25 mol
B) 1.50 mol
C) 0.75 mol
D) 2 mol
E) 2.5 mol
16. How many atoms are in 0.1 mol of argon (Ar)?
A) 6.02 × 10²³
B) 1.20 × 10²⁴
C) 6.02 × 10²²
D) 1.00 × 10²⁴
E) 3.01 × 10²⁴
17. How many atoms are in 5 mol of copper?
A) 3.01 × 10²³
B) 1.51 × 10²⁴
C) 5.00 × 10²³
D) 6.02 × 10²⁴
E) 3.01 × 10²⁴
18. 0.25 mol of sulfur contains how many atoms?
A) 1.20 × 10²⁴
B) 1.51 × 10²³
C) 6.02 × 10²³
D) 2.00 × 10²³
E) 1.50 × 10²²
19. How many moles of atoms are in 1.81 × 10²⁴ atoms of calcium?
A) 3 mol
B) 1 mol
C) 2 mol
D) 1.5 mol
E) 0.5 mol
20. How many atoms are in 1.25 mol of barium?
A) 7.52 × 10²³
B) 3.01 × 10²³
C) 6.02 × 10²³
D) 1.25 × 10²³
E) 1.50 × 10²⁴
Answers with Explanations
1. C) 6.02 × 10²³ — Avogadro's number is the number of atoms in 1 mole.
2. B) 1.20 × 10²⁴ — 2 mol × 6.02 × 10²³ atoms/mol
3. A) 3.01 × 10²³ — 0.5 mol × 6.02 × 10²³
4. B) 0.50 mol — Divide atoms by Avogadro’s number: (3.01 × 10²³) ÷ (6.02 × 10²³)
5. C) 3 mol — 1.806 × 10²⁴ ÷ 6.02 × 10²³ = 3
6. A) 4.52 × 10²³ — 0.75 mol × 6.02 × 10²³
7. C) 2 mol He — Highest mole count = more atoms
8. B) 0.01 mol — (6.02 × 10²²) ÷ (6.02 × 10²³) = 0.01 mol
9. A) 2.41 × 10²⁴ — 4 mol × 6.02 × 10²³
10. A) 9.03 × 10²³ — 1.5 mol × 6.02 × 10²³
11. B) 1.5 mol — 1.505 × 10²⁴ ÷ 6.02 × 10²³
12. C) 6.02 × 10²³ atoms / 1 mol — Standard conversion factor
13. E) 1.51 × 10²⁴ — 2.5 × 6.02 × 10²³
14. C) 2 mol — 1.204 × 10²⁴ ÷ 6.02 × 10²³
15. A) 1.25 mol — 7.53 × 10²³ ÷ 6.02 × 10²³
16. C) 6.02 × 10²² — 0.1 mol × 6.02 × 10²³
17. E) 3.01 × 10²⁴ — 5 mol × 6.02 × 10²³
18. B) 1.51 × 10²³ — 0.25 mol × 6.02 × 10²³
19. A) 3 mol — 1.81 × 10²⁴ ÷ 6.02 × 10²³
20. A) 7.52 × 10²³ — 1.25 mol × 6.02 × 10²³
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