Gibbs Free Energy (AQA A-Level Chemistry): Quizzes

📚Quizzes
Revision NotesModel AnswersQuizzesFlashcardsExam Questions
Gibbs Free Energy
Sign up to keep practising.Create a free account to play more quizzes and track your progress.

Practise the questions

10 questions from this quiz

Show

Which equation defines Gibbs free energy change?

ΔG=ΔH−TΔS\Delta G = \Delta H - T\Delta S

For a reaction to be feasible, what must be true about ΔG\Delta G?

Zero or negative

What does ΔG<0\Delta G < 0 indicate about a reaction?

Spontaneous

Which enthalpy change favours reaction feasibility?

ΔH<0\Delta H < 0 (releases energy)

Which entropy change favours reaction feasibility?

ΔS>0\Delta S > 0 (increases disorder)

To match units with ΔH\Delta H, how should ΔS\Delta S in J be converted?

Divide by 1000 to get kJ

Given ΔH=+50\Delta H = +50 kJ mol−1^{-1}, T=300T = 300 K, ΔS=+0.1\Delta S = +0.1 kJ K−1^{-1} mol−1^{-1}, find ΔG\Delta G.

+20+20 kJ mol−1^{-1}

Which formula calculates entropy change for vaporisation?

ΔS=ΔHT\Delta S = \frac{\Delta H}{T}

Which formula finds the temperature at which ΔG=0\Delta G = 0?

T=ΔHΔST = \frac{\Delta H}{\Delta S}

What does a negative slope in a ΔG\Delta G vs TT graph indicate?

Reaction may become feasible as T increases

Explore AQA A-Level Chemistry Revision Notes by Topics

Thermodynamics (A Level only)

Rate Equations (A Level only)

Equilibrium constant (Kp) for Homogeneous Systems (A Level only)

Electrode Potentials & Electrochemical Cells (A Level only)

Fundamentals of Acids & Bases (A Level only)

Further Acids & Bases Calculations (A Level only)

Explore AQA A-Level Chemistry Model Answers by Topics

Thermodynamics (A Level only)

Rate Equations (A Level only)

Equilibrium constant (Kp) for Homogeneous Systems (A Level only)

Electrode Potentials & Electrochemical Cells (A Level only)

Fundamentals of Acids & Bases (A Level only)

Further Acids & Bases Calculations (A Level only)

Explore AQA A-Level Chemistry Flashcards by Topics

Thermodynamics (A Level only)

Rate Equations (A Level only)

Equilibrium constant (Kp) for Homogeneous Systems (A Level only)

Electrode Potentials & Electrochemical Cells (A Level only)

Fundamentals of Acids & Bases (A Level only)

Further Acids & Bases Calculations (A Level only)

Explore AQA A-Level Chemistry Exam Questions by Topics

Thermodynamics (A Level only)

Rate Equations (A Level only)

Equilibrium constant (Kp) for Homogeneous Systems (A Level only)

Electrode Potentials & Electrochemical Cells (A Level only)

Fundamentals of Acids & Bases (A Level only)

Further Acids & Bases Calculations (A Level only)

Join 100,000+ A-Level students studying Quizzes with us.

Select your subjects, and get access to A+ resources today.