We’re being asked to calculate the value of ΔG° in kJ for the given reaction:

NH_{3}(g) + HBr(g) → NH_{4}Br(s)

We can use the following equation to solve for ** ΔG˚_{rxn}**:

$\overline{){\mathbf{\Delta G}}{{\mathbf{\xb0}}}_{{\mathbf{rxn}}}{\mathbf{=}}{\mathbf{\Delta G}}{{\mathbf{\xb0}}}_{\mathbf{f}\mathbf{,}\mathbf{}\mathbf{prod}}{\mathbf{-}}{\mathbf{\Delta G}}{{\mathbf{\xb0}}}_{\mathbf{f}\mathbf{,}\mathbf{}\mathbf{react}}}$

The values for **ΔG˚ _{f}** can be looked up in textbooks or online:

Given the values of ΔG_{f}° given below in kJ/mol calculate the value of ΔG° in kJ for the reaction,

NH_{3}(g) + HBr(g) => NH_{4}Br(s)

ΔG_{f}° (NH_{3}(g)) = -17

ΔG_{f}° (HBr(g)) = -52

ΔG_{f}° (NH_{4}Br(s)) = -177

a. 108 kJ

b. 212 kJ

c. -108 kJ

d. -212 kJ

e. -246 kJ

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What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Gibbs Free Energy concept. You can view video lessons to learn Gibbs Free Energy. Or if you need more Gibbs Free Energy practice, you can also practice Gibbs Free Energy practice problems.