Use Boyles Law


A gas sample has an intial volume of 250ml at 760 mmHg. Calculate the pressure required to change the volume to 150ml.
a
354 mm Hg
b
1567 mm Hg
c
1267 mm Hg
d
456 mm Hg

1 answer

Boyle's Law states that the pressure of a gas is inversely proportional to its volume when the temperature is held constant. This can be represented with the formula:

\[ P_1 V_1 = P_2 V_2 \]

where:

  • \( P_1 \) = initial pressure
  • \( V_1 \) = initial volume
  • \( P_2 \) = final pressure
  • \( V_2 \) = final volume

Given:

  • \( P_1 = 760 \) mmHg
  • \( V_1 = 250 \) mL
  • \( V_2 = 150 \) mL

We are solving for \( P_2 \):

First, rearranging the formula to solve for \( P_2 \):

\[ P_2 = \frac{P_1 V_1}{V_2} \]

Now plugging in the known values:

\[ P_2 = \frac{760 , \text{mmHg} \times 250 , \text{mL}}{150 , \text{mL}} \]

Calculating:

\[ P_2 = \frac{190000 , \text{mmHg} \cdot \text{mL}}{150 , \text{mL}} = \frac{190000}{150} \approx 1266.67 , \text{mmHg} \]

Rounding this value gives:

\[ P_2 \approx 1267 , \text{mmHg} \]

Thus, the pressure required to change the volume to 150 mL is approximately 1267 mmHg.

The correct answer is c) 1267 mmHg.