Question

3. A 2-kg steam water mixture at 1.0 MPaa is contained in an inflexible tank. Heat is

added until the pressure rises to 3.5 MPaa and the temperature to 400 o C. Determine:

a) Heat transferred (kJ), b) ΔH (kJ), c)ΔS (kJ/k)

Answer 1

$m = 2kg\\ P_1 = 1.0\ MPa\\ P_2 = 3.5\ MPa\\ U_1 = 2401.41\ kJ/kg\\ U_2= 2926.4\ kJ/kg\\ T = 400°C$

Heat transferred = $m(U_2-U_1) =$

$2(2926.4-2401.41) = 2(524.99)$

$= 1049.98\ kJ$