NEET 2025
- Exam
- NEET
- Year
- 2025
- Subject
- Chemistry
- Chapter
- Solutions
NEET 2025 · Chemistry · Solutions
5 moles of liquid X and 10 moles of liquid Y make a solution having...
5 moles of liquid X and 10 moles of liquid Y make a solution having a vapour pressure of 70 torr. The vapour pressures of pure X and Y are 63 torr and 78 torr respectively. Which of the following is true regarding the described solution?
Options
- AThe solution shows positive deviation.
- BThe solution shows negative deviation.
- CThe solution is ideal.
- DThe solution has volume greater than the sum of individual volumes.
Correct answer
B. The solution shows negative deviation.
Step-by-step solution
\begin{aligned}&\begin{aligned}& P_{s(\text{ calc.) }}=P_x^0 x_x+P_y^0 X_y \\
& =\frac{63 \times 5}{15}+78 \times \frac{10}{15}\\
& =21+52 \\
& =73 \\
& P_{s \text{ (obs.) }}=70 \\
& P_{s \text{ (obs.) }} < P_{s \text{ (calc.) }}
\end{aligned}\\
&\text{ -ve deviation }
\end{aligned}