In a mixture of gases, the pressure exerted by the individual gas is called — States of Matter and Gaseous State Chemistry Question

💡 Solution & Explanation

# Partial Pressure Definition The pressure exerted by an individual gas in a mixture of gases is called its **partial pressure**. ## Why B is Correct: **Dalton's Law of Partial Pressures** states that in a mixture of non-reacting gases, each gas behaves independently and exerts a pressure as if it alone occupied the entire volume. This individual pressure contribution is termed **partial pressure**. **Mathematical expression:** $$P_{total} = P_1 + P_2 + P_3 + ... + P_n$$ where $P_1, P_2, P_3...$ are the partial pressures of individual gases. **Example:** In air, oxygen exerts its own partial pressure (~0.21 atm) and nitrogen exerts its own partial pressure (~0.79 atm), regardless of their presence together. This is a fundamental concept in gas chemistry and applies to ideal gases under standard conditions.