Understanding Mole Fraction in Volatile Solutions

What’s inside this PDF?

Question: In a solution of two volatile components A and B, if the mole fraction of A is 0.6, what is the vapor pressure of the solution if the vapor pressure of pure A is 100 mmHg and that of pure B is 50 mmHg?

Options:

80 mmHg
90 mmHg
70 mmHg
60 mmHg

Correct Answer: 90 mmHg

Solution:

Using Raoult\'s Law, the vapor pressure of the solution is P_total = (0.6 * 100) + (0.4 * 50) = 60 + 20 = 80 mmHg.

Practice Questions

Q1

In a solution of two volatile components A and B, if the mole fraction of A is 0.6, what is the vapor pressure of the solution if the vapor pressure of pure A is 100 mmHg and that of pure B is 50 mmHg?

80 mmHg
90 mmHg
70 mmHg
60 mmHg

Questions & Step-by-Step Solutions

In a solution of two volatile components A and B, if the mole fraction of A is 0.6, what is the vapor pressure of the solution if the vapor pressure of pure A is 100 mmHg and that of pure B is 50 mmHg?

Step 1: Identify the mole fraction of component A, which is given as 0.6.
Step 2: Calculate the mole fraction of component B. Since the total mole fraction must equal 1, the mole fraction of B is 1 - 0.6 = 0.4.
Step 3: Identify the vapor pressure of pure component A, which is given as 100 mmHg.
Step 4: Identify the vapor pressure of pure component B, which is given as 50 mmHg.
Step 5: Use Raoult's Law to calculate the partial vapor pressure of A in the solution: Partial pressure of A = mole fraction of A * vapor pressure of pure A = 0.6 * 100 mmHg = 60 mmHg.
Step 6: Use Raoult's Law to calculate the partial vapor pressure of B in the solution: Partial pressure of B = mole fraction of B * vapor pressure of pure B = 0.4 * 50 mmHg = 20 mmHg.
Step 7: Add the partial pressures of A and B to find the total vapor pressure of the solution: P_total = Partial pressure of A + Partial pressure of B = 60 mmHg + 20 mmHg = 80 mmHg.

Raoult's Law – Raoult's Law states that the vapor pressure of a solution is equal to the sum of the partial pressures of each component, which can be calculated using the mole fraction and the vapor pressure of the pure components.

In a solution of two volatile components A and B, if the mole fraction of A is 0

What’s inside this PDF?

In a solution of two volatile components A and B, if the mole fraction of A is 0

Practice Questions

Questions & Step-by-Step Solutions

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