The enthalpy of vaporization of water at 200°C is 8.33 BTU/lb.

Question

What is the value expressed in kJ/mol?

Answer 1

To convert from BTU/lb to kJ/mol, we first need to convert from lb to mol.

The molar mass of water is approximately 18.015 g/mol.

1 lb = 0.453592 kg = 453.592 g
1 mol of water = 18.015 g

So,
453.592 g of water = 453.592 g / 18.015 g/mol = 25.17 mol

Next, we can convert from BTU to kJ.

1 BTU = 1.055056 kJ

Therefore, the conversion factor from BTU/lb to kJ/mol is:
8.33 BTU/lb * (1.055056 kJ / 1 BTU) = 8.781 kJ/lb

Finally, we can calculate the value expressed in kJ/mol:
8.781 kJ/lb * 1 lb / 25.17 mol = 0.348 kJ/mol

So, the value expressed in kJ/mol is approximately 0.348 kJ/mol.