Question

When $1$ mole gas is heated at constant volume, temperature is raised from $298K$ to $308K$. Heat supplied to the gas is $500J$. Then which statement is correct?

• A. $q=W=500J,\Delta U=0$
• B. $q=\Delta U=500J,W=0$
• C. $q=\Delta U=-500J,W=0$
• D. $\Delta U=0,q=W=-500J$

Answer 1

Answer: (B)

$q=\Delta U=500J,W=0$

From first law of thermodynamics:

$\Delta U=q+W$

In the given problem, $q=500J$

$W=-p\Delta V=0,\Delta V=0$

So, $\Delta U=q=500J$