Answer
For the first process (150°C to 250°C): $dh = 97.51\ kJ/kg$
For the second process (0°C to 100°C): $dh = 92.77\ kJ/kg$
The pressure doesn't have any effect in these processes.
Work Step by Step
From table A-2c, for oxygen:
$\bar{c}_p = a+bT+cT^2+dT^3$
$dh = \frac{1}{M}\int \bar{c}_pdT$
$dh = \frac{1}{M}(aT+b/2.T^2+c/3.T^3+d/4.T^4)|_{T_1}^{T_2}$
For the first process (150°C to 250°C):
$dh = 97.51\ kJ/kg$
For the second process (0°C to 100°C):
$dh = 92.77\ kJ/kg$
As it is known from the theory, and reflected in the $\bar{c}_p$ equation, the pressure doesn't have any effect in these processes.
