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Dalton’s law of partial pressures: write the correct relation Let pb be barometric pressure, pa the partial pressure of dry air, and pv the partial pressure of water vapour in a gas mixture at the same location. Choose the correct equation.

Difficulty: Easy

p_b = p_a − p_v
p_b = p_a + p_v
p_b = p_a × p_v
p_b = p_a / p_v

Correct Answer: p_b = p_a + p_v

Explanation:

Concept/ApproachDalton’s law for ideal gas mixtures: the total pressure equals the sum of the partial pressures of the components.

Thereforep_b = p_a + p_v.

Common pitfallSubtracting or multiplying partial pressures has no basis in Dalton’s law.

Final Answerp_b = p_a + p_v

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Dalton’s law of partial pressures: write the correct relation Let p<sub>b</sub> be barometric pressure, p<sub>a</sub> the partial pressure of dry air, and p<sub>v</sub> the partial pressure of water vapour in a gas mixture at the same location. Choose the correct equation.

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