Gibbs free energy practice problems

Chemistry Unit 9. Try each one, then open the worked solution. The Credit Sprint app generates unlimited new versions with fresh numbers.

Problem 1.

For a reaction, ΔH = -163 kJ and ΔS = 22 J/K. What is ΔG (in kJ) at 350 K?

Show solution

ΔG = ΔH − TΔS = -163 − (350)(0.022) = -171 kJ.

Problem 2.

For a reaction, ΔH = -198 kJ and ΔS = 125 J/K. What is ΔG (in kJ) at 400 K?

Show solution

ΔG = ΔH − TΔS = -198 − (400)(0.125) = -248 kJ.

Problem 3.

For a reaction, ΔH = -94 kJ and ΔS = -63 J/K. What is ΔG (in kJ) at 500 K?

Show solution

ΔG = ΔH − TΔS = -94 − (500)(-0.063) = -62.5 kJ.

Problem 4.

For a reaction, ΔH = -191 kJ and ΔS = -90 J/K. What is ΔG (in kJ) at 500 K?

Show solution

ΔG = ΔH − TΔS = -191 − (500)(-0.09) = -146 kJ.

Problem 5.

For a reaction, ΔH = -130 kJ and ΔS = 56 J/K. What is ΔG (in kJ) at 350 K?

Show solution

ΔG = ΔH − TΔS = -130 − (350)(0.056) = -150 kJ.

Problem 6.

For a reaction, ΔH = -176 kJ and ΔS = 78 J/K. What is ΔG (in kJ) at 298 K?

Show solution

ΔG = ΔH − TΔS = -176 − (298)(0.078) = -199 kJ.