Mole Concept Practice

8 problems · instant feedback · full explanations

The mole lets chemists count particles by weighing them. Work through these eight problems to get comfortable converting between mass, moles, and number of particles. Each solution shows the full working so you can check your method, not just your answer.

Q1.
How many particles are present in exactly one mole of any substance?

Multiple choice · Beginner

Q2.
How many moles are in 18.0 g of water (H2O)?

Numerical answer (mol) · Easy

Q3.
What is the molar mass of carbon dioxide, CO2?

Multiple choice · Easy

Q4.
The molar mass of an element in grams per mole is numerically equal to its atomic mass in atomic mass units.

True / False · Beginner

Q5.
What mass of sodium chloride (NaCl) contains 2.50 mol?

Numerical answer (g) · Easy

Q6.
A sample contains 0.50 mol of iron atoms. How many iron atoms is that?

Multiple choice · Medium

Q7.
One mole of O2 and one mole of CO2 contain the same number of molecules.

True / False · Easy

Q8.
How many carbon atoms are in 12.0 g of pure carbon-12?

Numerical answer (atoms) · Medium

Mole Concept Practice

Q1. How many particles are present in exactly one mole of any substance?

Q2. How many moles are in 18.0 g of water (H2O)?

Q3. What is the molar mass of carbon dioxide, CO2?

Q4. The molar mass of an element in grams per mole is numerically equal to its atomic mass in atomic mass units.

Q5. What mass of sodium chloride (NaCl) contains 2.50 mol?

Q6. A sample contains 0.50 mol of iron atoms. How many iron atoms is that?

Q7. One mole of O2 and one mole of CO2 contain the same number of molecules.

Q8. How many carbon atoms are in 12.0 g of pure carbon-12?