Question

The diagram given below represents pressure vs composition phase diagram (at constant temperature)
Which is/are correct among the following?

• A. Point $m_A$ represents the composition of 'A' in its vapour state
• B. Point $m_A$ represents the composition of 'A' in its liquid state
• C. Point $n_A$ represents the composition of 'A' in its vapour state
• D. Point $n_A$ represents the composition of 'A' in its liquid state

Answer 1

Answer: (B), (C)

Point $n_A$ represents the composition of 'A' in its vapour state

The pressure vs composition phase diagram (at constant temperature) is represented as;

Here $L$ is the liquid curve and $V$ is the vapour curve.
Point $m_A$ corresponds to ${\chi }_A$ i.e. mole fraction of A in liquid state
Point $n_A$ corresponds to $y_A$ i.e. mole fraction of A in vapour state