The pressure of water is increased from 100 kPa to 900 kPa by a pump. The temperature of water also increases by 0.15°C. The density of water is 1 kg/L and its specific heat is cp = 4.18 kJ/kg⋅°C. The enthalpy change of the water during this process is _____ kJ/kg. Solve this problem using appropriate software.

Respuesta :

Answer:

The enthalpy change of the water during the process is 1.4 kJ/kg

Explanation:

The enthalpy change of the water during the process can be determined from

[tex]\Delta H = \frac{\Delta P}{\rho} + C_{p} \Delta T[/tex]

Where

[tex]\Delta H[/tex] is the enthalpy change

[tex]\Delta P[/tex] is the change in pressure

[tex]\rho[/tex] is the density

[tex]C_{p}[/tex] is the specific heat

and [tex]\Delta T[/tex] is the temperature change

From the question

[tex]\Delta P[/tex] = 900 kPa - 100 k Pa

[tex]\Delta P[/tex] = 800 kPa

[tex]\rho[/tex] = 1 kg/L = 1kg/dm³ = 1000 kg/m³

[tex]C_{p}[/tex] = 4.18 kJ/kg.°C

[tex]\Delta T[/tex] = 0.15 °C

∴[tex]\Delta H = \frac{\Delta P}{\rho} + C_{p} \Delta T[/tex]

[tex]\Delta H = \frac{800}{1000} +4.18 \times 0.15[/tex]

[tex]\Delta H = 0.8 + 0.627\\[/tex]

[tex]\Delta H = 1.4 kJ /kg[/tex]

Hence, the enthalpy change of the water during the process is 1.4 kJ/kg