Question

A mass of gas has a volume of 4 m3, a temperature of 290 K, and an absolute pressure of 475 kPa. When the gas is allowed to expand to 6.5 m3, its new temperature is 277 K. What's the absolute pressure of the gas after expansion? A. 104.1 kPa B. 279.2 kPa C. 293.9 kPa D. 178.5 kPa

Answer 1

Answer : The correct option is, (B) 279.2 Kpa

Solution : Given,

Initial pressure of gas = 475 Kpa

Initial volume of gas = $4m^3$

Final volume of gas = $6.5m^3$

Initial temperature of gas = 290 K

Final temperature of gas = 277 K

Using ideal gas equation :

Formula used :

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

where,

$P_1$ = initial pressure of gas

$P_2$ = final pressure of gas

$V_1$ = initial volume of gas

$V_2$ = final volume of gas

$T_1$ = initial temperature of gas

$T_2$ = final temperature of gas

Now put all the given values in the above formula, we get the final pressure of the gas.

$\frac{(475Kpa)\times (4m^3)}{290K}=\frac{P_2\times (6.5m^3)}{277K}$

$P_2=279.2Kpa$

Therefore, the absolute pressure of the gas after expansion is, 279.2 Kpa

Answer 2

A mass of gas has a volume of 4 m3, a temperature of 290 K, and an absolute pressure of 475 kPa. When the gas is allowed to expand to 6.5 m3, its new temperature is 277 K. The absolute pressure of the gas after expansion is 279.2 kPa. The answer is letter B