How do you calculate the molar enthalpy of condensation (DeltaH_(cond)ΔHcond) for ammonia when 100.0 g of NH_3 gas turn into a liquid at its boiling point?

68,500 J of energy are released in the process.

1 Answer
Jun 19, 2017

By calculating the quotient, "energy released"/"moles of ammonia"......and get DeltaH_"condensation"=-11.7*kJ*mol^-1

Explanation:

We interrogate the process...........

NH_3(g) rarr NH_3(l)+Delta_"condensation"

We want DeltaH_"condensation" with units of kJ*mol^-1.

We have parameters for a 100*g mass of ammonia.....

And thus, (-68500*J)/((100.0*g)/(17.03*g*mol^-1))=-11665.6*J*mol^-1, i.e. -11.7*kJ*mol^-1.