Question

If w is the work done and q is the heat change during isothermal expansion of an ideal gas to triple its volume at $298K$ and $1atm$. Which pof the following is always true ?

• A. $e=3q$
• B. $q=3w$
• C. $w+q=0$
• D. $w\times =3$

Answer 1

Answer: (C)

$w+q=0$

Solution:- (C) $w+q=0$

In an isothermal proces, the temperature remains constant, thus,

$\Delta U=0$

Therefore from first law of thermodynamics,

$\Delta U=q+w$

$\because \Delta U=0$

$\therefore q=-w$

$\Rightarrow q+w=0$