Ased on the thermodynamic properties provided for methanol (below and to the right), determine from the following list the equation(s) necessary to calculate the amount of energy needed for 22.8 kg of methanol from all gas at 65°c to –112°c.

The necessary equations necessary are explained in each step in the solution.

Explanation:

For conversion of methanol gas at 65°C to -112°C

the equations would be as follows,

step 1 : gas at 65°C to liquid at 65°C

q = n(-37 kJ/mol)

step 2 : liquid at 65°C to liquid at -94°C

q = n(81.1 J/mol°C), where dT is negative

step 3 : liquid at -94°C to solid at -94°C

q = n(-3.18 kJ/mol)

step 4 : solid at -94°C to solid at -112°C

q = n(48.7 J/mol°C), where dT is negative