Question

9. A gas occupies 8.2 L at 48°C and 750. torr. What volume will the gas occupy at STP?

Answer 1

Answer: The volume the gas will occupy at STP is 6.9 L

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 = 750 torr = 0.99 atm  (760torr=1atm)

$P_2$ = final pressure of gas = 1 atm (at STP)

$V_1$ = initial volume of gas = 8.2 L

$V_2$ = final volume of gas = ?

$T_1$ = initial temperature of gas = $48^oC=273+48=321K$

$T_2$ = final temperature of gas = $273K$ (at STP)

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

$\frac{0.99\times 8.2}{321}=\frac{1\times V_2}{273}$

$V_2=6.9$

Thus volume the gas will occupy at STP is 6.9 L