Counting Particles with Moles Worksheet

Question 1

How many CO₂ molecules are in 0.500 mol of CO₂?

1. 1.20 × 10²³
2. 3.01 × 10²³
3. 6.02 × 10²³
4. 1.20 × 10²⁴

Question 2

A sample contains 1.204 × 10²⁴ helium atoms. Find the amount of helium in moles.

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Question 3

What kind of entity does one mole of solid sodium chloride count?

1. Individual Na atoms only
2. Individual Cl atoms only
3. NaCl molecules
4. NaCl formula units

Question 4

Explain why one mole of O₂ molecules contains two moles of O atoms.

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Question 5

Which pair contains equal numbers of molecules?

1. P and Q
2. P and R
3. Q and R
4. All three samples

Question 6

Calculate the number of oxygen atoms in sample P. Show how the formula affects the count.

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Question 7

How does the number of NaCl formula units in R compare with the number of CO₂ molecules in P?

1. Half as many
2. The same number
3. Twice as many
4. Four times as many

Question 8

Compare the number of chloride ions in sample R with the number of NaCl formula units in the same sample. Explain using the formula.

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