Dalton's law of partial pressures
Grade 10 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.
A tank's gas mix has partial pressures of 0.6 atm (N₂), 0.3 atm (O₂) and 0.1 atm (other gases). What is the total pressure, Ari?
A balloon's gas has partial pressures of 0.39 atm (N₂), 0.105 atm (O₂) and 0.005 atm (other gases). What is the total pressure, Kira?
A balloon holds N₂ at 0.78 atm and O₂ at 0.21 atm, plus 0.01 atm of other gases. What is the total pressure, Jun?
- 0.99 atm, leaving out the other gases
- 0.78 atm, the largest part alone
- 1.00 atm, the sum of the parts
With equal moles in one container, which pushes harder: O₂ or the heavier CO₂, Milo?
- Neither: equal moles give equal partial pressures
- The CO₂, since its particles are heavier
- The O₂, since its particles are lighter
About what share of dry air is nitrogen, by NOAA's figures, Noah?
- About 50%
- About 21%
- About 78%
About what share of dry air is oxygen, by NOAA's figures, Pia?
- About 21%
- About 1%
- About 78%
Which gas is the third most common in dry air, at 0.934%, Ren?
- Carbon dioxide
- Argon
- Oxygen
A tank has 1 mol of O₂ and 3 mol of N₂. What is O₂'s mole fraction, Tala?
- 0.75, the N₂ share
- 0.33, from 1 ÷ 3
- 0.25, from 1 ÷ 4
O₂'s mole fraction is 0.25 and the total pressure is 2.0 atm. What is O₂'s partial pressure, Zee?
- 1.5 atm, the N₂ share
- 0.5 atm
- 2.0 atm, the whole total
Why is a gas's share of the pressure equal to its share of the moles, Esme?
- The main gas alone adds pressure
- Heavier particles add more pressure
- Each particle adds to the pressure the same way

