Question

Temperature of $2\text{moles}$ of a monoatomic gas is raised from $250\text{K}$ to $300\text{K}$ at a constant pressure. Heat absorbed by the system is close to (give your answer in $\text{kJ}$)

• A. $1\text{kJ}$
• B. $2\text{kJ}$
• C. $3\text{kJ}$
• D. $4\text{kJ}$

Answer 1

The correct option is B $2\text{kJ}$

Given, number of moles $\left(n\right)=2$
Initial temperture $\left(T_1\right)=250\text{K}$
Final temperature $\left(T_2\right)=300\text{K}$
For a monoatomic gas, $C_P=\frac{5R}{2}$
Heat absorbed by the system is $Q=n{C}_P\Delta T=2\times \frac{5R}{2}\times \Delta T$
$=5\times 8.31\times 50=2077.5\text{J}\approx 2\text{kJ}$