Question

An ideal gas originally at 0.85 atm and 66°C was allowed to expand until its final volume, pressure and temperature were 94.0mL, 456 mmHg and 113°F. What was the original volume in liters?

Answer 1

Answer: The original volume in liters was 0.0707L

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 = 0.85 atm

$P_2$ = final pressure of gas = 456 mm Hg = 0.60 atm   (760mmHg=1atm)

$V_1$ = initial volume of gas = ?

$V_2$ = final volume of gas = 94.0 ml

$T_1$ = initial temperature of gas = $66^oC=273+66=339K$

$T_2$ = final temperature of gas = $113^oF=318K$  $(32^0F=273K)$

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

$\frac{0.85\times V_1}{339}=\frac{0.60\times 94.0}{318}$

$V_1=70.7ml=0.0707L$   (1L=1000ml)

Thus the original volume in liters was 0.0707L