Question

calcute the molar enthalpy of condensation (H condensation) for ammonia when 50.0g of NH3 gas turn into a liquid at its bioling piont. 68.500J of energy are releasd in the process

Answer 1

To calculate the molar enthalpy of condensation (ΔH condensation), we first need to calculate the moles of ammonia (NH3) gas using its molar mass.

The molar mass of NH3 is:
Nitrogen (N): 14.01 g/mol
Hydrogen (H): 1.01 g/mol
3 Hydrogens in NH3

Molar mass of NH3 = (14.01 g/mol) + (3(1.01 g/mol))
Molar mass of NH3 = 17.03 g/mol

Now, we can calculate the moles of NH3 gas:
moles of NH3 = mass / molar mass
moles of NH3 = 50.0 g / 17.03 g/mol
moles of NH3 = 2.93 mol

Since the reaction is the condensation of NH3 gas to a liquid, we know that the molar enthalpy of condensation (∆H condensation) is given by:
ΔH condensation = -68.500 J / moles of NH3

Substituting the values:
ΔH condensation = -68.500 J / 2.93 mol
ΔH condensation = -23,400 J/mol

Hence, the molar enthalpy of condensation for ammonia is -23,400 J/mol.