Question

The state of an ideal gas was changed isobarically. The graph depicts three such isobaric lines. Which of the following is true about the pressures of the gas?

• A. $p_{1} = p_{2} = p_{3}$
• B. $p_{1}> p_{2}> p_{3}$
• C. $p_{1} < p_{2} < p_{3}$
• D. $p_{1}/p_{2} = p_{3} /p_{1}$

Answer 1

Answer: (C)

Equation of state for ideal gas is
$pV=nRT\Rightarrow V=\frac{nR}{p}.T$
This is equation of line with slope $=\frac{nR}{p}$
$\Rightarrow $ Slope $\propto \frac{1}{p}$
So, from graph, $p_{3} < p_{2} < p_{1} $