Partial pressure is the pressure exerted by ______ within a mixture of gases.

• A. an individual gas
• B. the most abundant gas
• C. all gases combined
• D. the heaviest gas

Answer: (A)

Verified step by step guidance

1. Understand the concept of partial pressure: it refers to the pressure that a single gas exerts within a mixture of gases, independent of the other gases present.
2. Recall Dalton's Law of Partial Pressures, which states that the total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture.
3. Recognize that each gas in a mixture behaves as if it alone occupies the entire volume, contributing its own pressure proportional to its mole fraction.
4. Therefore, the partial pressure is specifically the pressure exerted by an individual gas, not by all gases combined or by the most abundant or heaviest gas.
5. Conclude that the correct completion of the sentence is: 'Partial pressure is the pressure exerted by an individual gas within a mixture of gases.'