Question
Question: The specific heat of air at constant volume is 0.172 Cal g–1 °C–1. The change in internal energy whe...
The specific heat of air at constant volume is 0.172 Cal g–1 °C–1. The change in internal energy when 5 g of air is heated from 0° C of 4°C at constant volume is
A
28.8 J
B
14.4 J
C
7.2 J
D
3.51 J
Answer
14.4 J
Explanation
Solution
: As constant volume,
}{dQ = mC_{V}\Delta T = 5 \times 0.172 \times 4cal }{= 5 \times 0.172 \times 4 \times 4.2J }{= 14.4J}$$ $${\therefore dU = dQ - dW = 14.4 - 0 }{= 14.4J}$$