Question

1. choose the best answer. use significant figures.

use the combined gas law to solve for the initial celsius temperature.
$p_1 = 125$ kpa
$v_1 = 125$ ml
$t_1 = ?$
$p_2 = 100.00$ kpa
$v_2 = 100.00$ ml
$t_2 = 75.0 \\ ^\circ c$
$271 \\ ^\circ c$
$223 \\ ^\circ c$
$544 \\ ^\circ c$

Explanation:

Step1: Convert T₂ to Kelvin

$T_2 = 75.0 + 273.15 = 348.15\ \text{K}$

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 $T_1$:
$T_1 = \frac{P_1V_1T_2}{P_2V_2}$

Step3: Substitute values into formula

$T_1 = \frac{125\ \text{kPa} \times 125\ \text{mL} \times 348.15\ \text{K}}{100.00\ \text{kPa} \times 100.00\ \text{mL}}$

Step4: Calculate T₁ in Kelvin

$T_1 = \frac{125 \times 125 \times 348.15}{100.00 \times 100.00} = 543.984375\ \text{K}$

Step5: Convert T₁ to Celsius

$T_1 = 543.984375 - 273.15 = 270.834375\ \text{°C}$

Step6: Apply significant figures

Round to 3 significant figures: $271\ \text{°C}$

Answer:

271 °C