JEE PYQ: Thermodynamics Question 19
Question 19 - 2019 (08 Apr Shift 1)
For silver, $C_p (\text{J K}^{-1}\text{ mol}^{-1}) = 23 + 0.01T$. If the temperature (T) of 3 moles of silver is raised from 300 K to 1000 K at 1 atm pressure, the value of $\Delta H$ will be close to:
(1) 62 kJ
(2) 16 kJ
(3) 21 kJ
(4) 13 kJ
Show Answer
Answer: (1)
Solution
Given $n = 3$, $T_1 = 300$, $T_2 = 1000$. $\Delta H = \int nC_p dT$. $\Delta H = n\int_{300}^{1000}(23 + 0.01T)dT = 3\left[23T + \dfrac{0.01T^2}{2}\right]_{300}^{1000} = 3[16100 + 4550] = 3 \times 20650 = 61950$ J $= 61.95$ kJ $\approx 62$ kJ.
BETA
