Question

How much heat, in joules, must be added to 0.250 mol of Ar(g) to raise its temperature from ${20}^{o}C$ to ${36}^{o}C$ at constant pressure?

• A. 50
• B. 83.2
• C. 187
• D. 200

Answer 1

The correct option is B 83.2

$Ar=$ monoatomic ideal gas $C_V=\frac{3}{2}R$

At constant pressure, $q=\Delta H={nC}_P\Delta T$

$q=\left(0.25mole\right)\frac{5}{2}.\left(8.314J/Kmole\right)\left(16K\right)=83.14J\approx 83.2J$

Hence, option B is correct