Question

A sample of nitrogen gas had a volume of 500. mL, a pressure in its closed container of 740 torr, and a temperature of 25 °C. What was the new volume of the gas when the temperature was changed to 50 °C and the new pressure is 760 torr

Answer 1

Answer : The new volume of gas was, 523 mL

Explanation :

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1$ = initial pressure of gas = 740 torr

$P_2$ = final pressure of gas = 760 torr

$V_1$ = initial volume of gas = 500 mL

$V_2$ = final volume of gas = ?

$T_1$ = initial temperature of gas = $25^oC=273+25=298K$

$T_2$ = final temperature of gas = $50^oC=273+50=320K$

Now put all the given values in the above equation, we get:

$\frac{740torr\times 500mL}{298K}=\frac{760torr\times V_2}{320K}$

$V_2=522.78torr\approx 523mL$

Thus, the new volume of gas was, 523 mL