Question

What enthalpy change is occurring?

I got -39.86 kJ

Answer 1

`-39.9color(white)(l)kJ` of heat are evolved.

Explanation:

Start by converting 120.0 g of `NH_3` to moles.

The molar mass of ammonia is 17.031 g/mol.

`(120.0color(white)(l)gcolor(white)(l)NH_3)/1times(1color(white)(l)molcolor(white)(l)NH_3)/(17.031color(white)(l)gcolor(white)(l)NH_3)=7.046color(white)(l)molcolor(white)(l)NH_3`

The molar enthalpy is -5.66 kJ/mol. So, calculate how much heat is evolved when 7.046 moles of ammonia react.

`(7.046color(white)(l)molcolor(white)(l)NH_3)/1times(-5.66color(white)(l)kJ)/(1color(white)(l)molcolor(white)(l)NH_3)=-39.9color(white)(l)kJ`