Question

If R is universal gas constant, the amount of heat neaded to raise the temperature of 2 moles of an ideal monoatomic gas from 273 K to 373 K when no work is done is

• A. 100 R
• B. 150 R
• C. 300 R
• D. 500 R

Answer 1

Answer: (C)

300 R

Answer 2

: As no work is done, therefore, $\Delta W = 0$

According to first law of thermodynamics

$\Delta Q = \Delta U + \Delta W = \Delta U = nC_{V}\Delta T = n\left( \frac{R}{\gamma - 1} \right)\Delta T$

Here, $n = 2,\gamma = \frac{5}{3}$

}{\Delta Q = 2 \times \frac{R}{\left( \frac{5}{3} - 1 \right)} \times 100 = 300R}$$