Question

Certain amount of a gas confined in a piston-filled cylinder is heated from ${27}^0$C to ${127}^0$C keeping its pressure constant and the gas expanded against a constant pressure doing 4.157 kJ of work on surroundings. Find the number of moles of gas present in the cylinder ?

• A. 4
• B. 5
• C. 6
• D. 7

Answer 1

The correct option is B 5

$W=-P$$\Delta V$

$W=-nR\Delta T$

or, $n=$$\frac{4.157\times {10}^3}{8.314\times 100}=5$