Question

At 25°C, gas in a rigid cylinder with a movable piston has a volume of 145 mL and a pressure of 125 kPa. Then the gas is compressed to a volume of 80. mL. What is the new pressure of the gas if the temperature is held at 25°C?(1) 69 kPa (3) 160 kPa (2) 93 kPa (4) 230 kPa
The first person didn't make sense as P1v1 = P2v2 isnt the same thing as P1V1/V2 that literally doesn't make sense, so could someone help me please!

Answer 1

Answer:

(4) 230 kPa

Explanation:

The temperature is constant, so the only variables are pressure and volume.

We can use Boyle’s Law.

$p_{1}V_{1} = p_{2}V_{2}$

Divide both sides of the equation by $V_{2}$.

$p_{2} = p_{1} \times \frac{V_{1}}{ V_{2}}$

$p_{1} = \text{145 kPa}; V_{1} = \text{125 cm}^{3}}$

$p_{2} = ?; V_{2} = \text{80. cm}^{3}$

$p_{2} = \text{145 kPa} \times \frac{\text{125 cm}^{3}}{\text{80. cm}^{3}} = \textbf{230 kPa}$