Answer
The partial pressure of the helium in that mixture is equal to 0.30 atm.
Work Step by Step
1. Identify the equation that we will use to solve this problem.
- The sum of the partial pressures.
$P_{total} = P_1 + P_2 + P_3 + ...$
- For this mixture:
$P_{total}(initial) = P_{O_2} + P_{N_2} + P_{Ne}$
$P_{total}(final) = P_{O_2} + P_{N_2} + P_{Ne} + P_{He}$
- We can put these 2 equations together to get:
$P_{total}(final) = P_{total}(Initial) + P_{He}$
2. Solve for $P_{He}$:
$P_{total}(final) - P_{total}(Initial) = P_{He}$
3. Substitute the given values into the equation:
$1.50 \space atm - 1.20 \space atm = P_{He}$
$P_{He} = 0.30 \space atm$
