题目
26.2 mol N₂(g)可看作理想气体,从298 K,200 kPa的始态,绝热可逆压缩压缩到600 kPa,试求该过程的Q,W,ΔU和ΔH。(重要提示:请将计算题答案拍照上传。)
26.2 mol N₂(g)可看作理想气体,从298 K,200 kPa的始态,绝热可逆压缩压缩到600 kPa,试求该过程的Q,W,ΔU和ΔH。(重要提示:请将计算题答案拍照上传。)
题目解答
答案
根据绝热可逆过程公式:
\[
\frac{T_2}{T_1} = \left( \frac{p_2}{p_1} \right)^{\frac{\gamma - 1}{\gamma}} = 3^{0.2857} \approx 1.369
\]
\[
T_2 = 1.369 \times 298 \, \text{K} \approx 408 \, \text{K}
\]
由 $Q = 0$,得:
\[
\Delta U = n C_V (T_2 - T_1) = 2 \times 20.785 \times 110 = 4.57 \, \text{kJ}
\]
\[
W = \Delta U = 4.57 \, \text{kJ}
\]
\[
\Delta H = n C_P (T_2 - T_1) = 2 \times 29.1 \times 110 = 6.40 \, \text{kJ}
\]
最终结果:
\[
Q = 0, \quad W = 4.57 \, \text{kJ}, \quad \Delta U = 4.57 \, \text{kJ}, \quad \Delta H = 6.40 \, \text{kJ}
\]