Practice Avogadro's Number in Chemistry
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
The defined number of particles in exactly one mole of any substance: 6.022 \times 10^{23}.
A mind-bogglingly large number — but it's exactly the right size to make atomic counting practical.
Example 1
easyHow many molecules are in 2.5 mol of \text{CO}_2?
Example 2
mediumHow many individual oxygen atoms are in 1.5 mol of \text{H}_2\text{O}?
Example 3
mediumHow many molecules are in 2.5 moles of water (\text{H}_2\text{O})? How many individual atoms is that?
Example 4
easyHow many atoms are in 0.50 mol of iron (Fe)?
Example 5
mediumHow many chloride ions are in 0.200 mol of \text{CaCl}_2?