Question

The enthalpy for the formation of 1 mole of NH3(aq) is -80.29 kJ/mol . What is the enthalpy for the formation of 3 moles of NH3(aq) ?

a) −518×103 kJ
b) -240.87 kJ
c) -26.76 kJ
d ) -83.29 kJ

Answer 1

Related Concepts

• Enthalpies of formation
• Thermochemistry
• Hess's Law

Solving the Question

We're given that the enthalpy of formation of 1 mol of NH3 (aq) is -80.29 kJ/mol. This is the amount of energy it takes to form 1 mol of NH3 (aq).

To determine the enthalpy required to form 3 mol of NH3 (aq), multiply -80.29 by 3:

`-80.29*3\\= -240.97`

Answer

b) -240.97 kJ