Question

How much heat, in joules, must be added to 0.250 mol of Ar(g) to raise its temperature from ${20}^{0}C$ to ${36.0}^0$ at constant pressure?

• A. 50
• B. 83.2
• C. 187
• D. 200

Answer 1

Answer: (B)

83.2

Solution:- (B) $83.2$

Given:-

No. of moles $\left(n\right)=0.25\text{mol}$

Initial temperature $\left(T_1\right)=20℃$

Final temperature $\left(T_2\right)=36℃$

$\Delta T=T_2-T_1=36-20=16$

$C_p=\frac{5}{2}R[\because \text{Argon is a monoatomic gas}]$

As we know that, at constant pressure,

$q=n{C}_p\Delta T$

$\therefore q=0.25\times \frac{5}{2}R\times 16=83.14J\approx 83.2J$

Hence the correct answer is $83.2J$.