What enthalpy change is occurring?

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I got -39.86 kJ

1 Answer
Mar 5, 2018

-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