I have a 500 L tank that can hold a fluid. How much heavier or lighter will the tank be if a. The tank holds water at 80C compared to if the water tank holds 5C water? b. The tank holds air at 80C compared to if the water tank holds 5C air? Assume the tank is vented in a way that the pressure remains at atmospheric pressure, given as 101.3 KPa.

water=14.1 kg

air=0.1348kg

Explanation:

Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ...)

through prior knowledge of two other properties such as pressure and temperature.

To solve this exercise we must find the specific volume of water and air in the two states and then subtract them and multiply them by the volume of the tank to find the change in mass, the following equation is inferred

Δm=V (ρ2-ρ1)

Where V = tank volume=500L=0.5m^3

ρ2 = density of fluid in state 2

ρ1=density of fluid in state 1

Δm=change of mass

for water

ρ1=971.8kg/m^3 (80C)

ρ2=1000kg/m^3 (5C)

Δm=0.5 (1000-971.8)

Δm=14.1 kg

for air

ρ1=0.9994kg/m^3 (80C)

ρ2=1.269kg/m^3 (5C)

Δm=0.5 (1.269-0.9994)

Δm=0.1348kg