Question

1. choose the best answer. use significant figures.

use the combined gas law to solve for the final pressure.
$p_1 = 720.0 \text{ mmhg}$
$v_1 = 256 \text{ ml}$
$t_1 = 25.0 \\ ^\circ\text{c}$
$p_2 = ?$
$v_2 = 250.0 \text{ ml}$
$t_2 = 50.0 \\ ^\circ\text{c}$
680 mmhg
1480 mmhg
799 mmhg

Explanation:

Step1: Convert temp to Kelvin

$T_1 = 25.0 + 273.15 = 298.15\ \text{K}$
$T_2 = 50.0 + 273.15 = 323.15\ \text{K}$

Step2: Rearrange combined gas law

The combined gas law is $\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2}$, rearranged to solve for $P_2$:
$P_2 = \frac{P_1V_1T_2}{V_2T_1}$

Step3: Substitute values into formula

$P_2 = \frac{720.0\ \text{mmHg} \times 256\ \text{mL} \times 323.15\ \text{K}}{250.0\ \text{mL} \times 298.15\ \text{K}}$

Step4: Calculate and apply sig figs

First compute the numerical value:
$\frac{720.0 \times 256 \times 323.15}{250.0 \times 298.15} \approx 799$

Answer:

799 mmHg