AP Chemistry Flashcards: Free Energy Of Dissolution

Study Free Energy Of Dissolution in AP Chemistry with focused flashcards that help you recognize the idea, recall the key rule, and apply it in practice-style prompts.

AP Chemistry

Free Energy Of Dissolution

0 mastered0 still learning

0% Complete

QUESTION

1/ 41

Calculate $\triangle G$ given $\triangle H = 10 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 50 \text{ J/mol·K}$ .

Tap card or press Space to flip

ANSWER

$\triangle G = -4.9 \text{ kJ/mol}$ . $\triangle G = 10000 - 298(50) = 10000 - 14900 = -4900$ J/mol.

How well did you know it?

Card 1 / 41

What this deck covers

This deck focuses on Free Energy Of Dissolution, giving you a quick way to review the definitions, rules, and examples that matter most for AP Chemistry.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

All flashcards

Flashcard 1: Calculate $\triangle G$ given $\triangle H = 10 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 50 \text{ J/mol·K}$ .

Answer: $\triangle G = -4.9 \text{ kJ/mol}$ . $\triangle G = 10000 - 298(50) = 10000 - 14900 = -4900$ J/mol.

Flashcard 2: Which quantity becomes zero at the dissolution equilibrium point?

Answer: $\triangle G$ . Free energy equals zero when forward and reverse rates are equal.

Flashcard 3: What is the primary driver of dissolution for ionic solids in water?

Answer: Entropy increase. Breaking crystal lattice increases disorder despite ion-water interactions.

Flashcard 4: Calculate $\triangle G$ with $\triangle H = 20 \text{ kJ/mol}$ , $T = 350 \text{ K}$ , $\triangle S = 70 \text{ J/mol·K}$ .

Answer: $\triangle G = -4.5 \text{ kJ/mol}$ . $\triangle G = 20000 - 350(70) = 20000 - 24500 = -4500$ J/mol.

Flashcard 5: Which parameter is zero for a process at equilibrium?

Answer: $\triangle G$ . At equilibrium, the free energy change equals zero.

Flashcard 6: Determine the spontaneity: $\triangle H = 5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 30 \text{ J/mol·K}$ .

Answer: Spontaneous. $\triangle G = 5000 - 298(30) = 5000 - 8940 = -3940$ J/mol, so spontaneous.

Flashcard 7: What is the sign of $\triangle H$ if dissolution absorbs heat?

Answer: $\triangle H > 0$ . Positive enthalpy indicates an endothermic heat-absorbing process.

Flashcard 8: What is indicated by a positive $\triangle G$ in dissolution?

Answer: Non-spontaneous process. Positive free energy means the process is thermodynamically unfavorable.

Flashcard 9: What determines the spontaneity of a dissolution process?

Answer: Sign of $\triangle G$ . Negative $\triangle G$ means spontaneous, positive means non-spontaneous.

Flashcard 10: Determine the spontaneity: $\Delta H = 5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\Delta S = 30 \text{ J/mol·K}$ .

Answer: Spontaneous. $\Delta G = 5000 - 298(30) = 5000 - 8940 = -3940$ J/mol, so spontaneous.

Flashcard 11: What is the sign of $\triangle G$ when $\triangle H < 0$ and $\triangle S > 0$ ?

Answer: $\triangle G < 0$ . Both terms favor spontaneity, making $\triangle G$ always negative.

Flashcard 12: Calculate $\triangle G$ when $\triangle H = 15 \text{ kJ/mol}$ , $T = 300 \text{ K}$ , $\triangle S = 60 \text{ J/mol·K}$ .

Answer: $\triangle G = -3 \text{ kJ/mol}$ . $\triangle G = 15000 - 300(60) = 15000 - 18000 = -3000$ J/mol.

Flashcard 13: What does a positive $\triangle S$ indicate about entropy in dissolution?

Answer: Entropy increases. Positive $\triangle S$ means the system becomes more disordered.

Flashcard 14: Determine the spontaneity: $\triangle H = 5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 30 \text{ J/mol·K}$ .

Answer: Spontaneous. $\triangle G = 5000 - 298(30) = 5000 - 8940 = -3940$ J/mol, so spontaneous.

Flashcard 15: State the condition for a dissolution to be spontaneous at all temperatures.

Answer: $\triangle H < 0$ , $\triangle S > 0$ . Exothermic enthalpy and positive entropy ensure spontaneity.

Flashcard 16: What is the sign of $\triangle G$ when dissolution is at equilibrium?

Answer: $\triangle G = 0$ . Zero free energy indicates the system has reached equilibrium.

Flashcard 17: Find the entropy change: $\triangle G = 10 \text{ kJ/mol}$ , $\triangle H = 15 \text{ kJ/mol}$ , $T = 298 \text{ K}$ .

Answer: $\triangle S = 16.78 \text{ J/mol·K}$ . $\triangle S = (\triangle H - \triangle G)/T = (15000 - 10000)/298 = 16.78$ J/mol·K.

Flashcard 18: What does a positive $\triangle S$ indicate about entropy in dissolution?

Answer: Entropy increases. Positive $\triangle S$ means the system becomes more disordered.

Flashcard 19: What is the relationship between $\triangle H$ and $\triangle S$ in spontaneous dissolution?

Answer: $\triangle H < T\triangle S$ . For spontaneity, the entropy term must overcome unfavorable enthalpy.

Flashcard 20: What is the unit of Gibbs free energy change?

Answer: Joules (J) or kilojoules (kJ). Energy units for thermodynamic quantities in the SI system.

Flashcard 21: State the effect on $\triangle G$ if both $\triangle H$ and $\triangle S$ are positive.

Answer: Depends on $T$ . Sign depends on whether $T\triangle S$ is greater or less than $\triangle H$ .

Flashcard 22: Which factor affects the sign of $\triangle G$ at constant pressure and temperature?

Answer: Enthalpy and entropy. Both enthalpy and entropy contributions determine free energy sign.

Flashcard 23: What effect does increased pressure have on gas solubility in liquids?

Answer: Increases solubility. Henry's law: gas solubility is directly proportional to pressure.

Flashcard 24: Identify the factor that primarily affects $\triangle S$ in dissolution.

Answer: Molecular disorder. Dissolution typically increases randomness as molecules spread out.

Flashcard 25: What does a negative $\triangle S$ for dissolution indicate?

Answer: Entropy decreases. Negative entropy change indicates decreased molecular disorder.

Flashcard 26: Identify the formula for entropy change.

Answer: $\triangle S = \frac{\triangle H - \triangle G}{T}$ . Rearranged form of the Gibbs free energy equation.

Flashcard 27: What does a positive $\triangle S$ indicate about entropy in dissolution?

Answer: Entropy increases. Positive $\triangle S$ means the system becomes more disordered.

Flashcard 28: Which parameter is affected by both enthalpy and entropy in dissolution?

Answer: Gibbs free energy ( $\triangle G$ ). Free energy depends on both $\triangle H$ and $T\triangle S$ terms.

Flashcard 29: Calculate $\triangle H$ given $\triangle G = -3 \text{ kJ/mol}$ , $T = 310 \text{ K}$ , $\triangle S = 80 \text{ J/mol·K}$ .

Answer: $\triangle H = 21.8 \text{ kJ/mol}$ . $\triangle H = \triangle G + T\triangle S = -3000 + 310(80) = 21800$ J/mol.

Flashcard 30: What type of process occurs when $\triangle G > 0$ ?

Answer: Non-spontaneous process. Positive free energy indicates thermodynamically unfavorable conditions.

Flashcard 31: What is the significance of $\triangle G = 0$ in dissolution?

Answer: Equilibrium state. Zero free energy indicates the system is at thermodynamic equilibrium.

Flashcard 32: Calculate the enthalpy change: $\Delta G = -5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\Delta S = 20 \text{ J/mol·K}$ .

Answer: $\Delta H = 1.96 \text{ kJ/mol}$ . $\Delta H = \Delta G + T \Delta S = -5000 + 298(20) = 1960$ J/mol.

Flashcard 33: Determine the spontaneity: $\triangle H = 5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 30 \text{ J/mol·K}$ .

Answer: Spontaneous. $\triangle G = 5000 - 298(30) = 5000 - 8940 = -3940$ J/mol, so spontaneous.

Flashcard 34: What is the effect of increasing temperature on an exothermic dissolution?

Answer: Decreases solubility. Le Chatelier's principle: heat addition shifts equilibrium away from products.

Flashcard 35: Which variable increases the dissolution rate in endothermic reactions?

Answer: Temperature. Higher kinetic energy from temperature increases dissolution rate.

Flashcard 36: How does the dissolution of a gas in a liquid typically affect $\Delta S$ ?

Answer: $\Delta S$ decreases. Gas molecules become more ordered when dissolved in liquid.

Flashcard 37: What is the formula for Gibbs free energy change?

Answer: $\triangle G = \triangle H - T\triangle S$ . Fundamental thermodynamic equation relating free energy to enthalpy and entropy.

Flashcard 38: In dissolution, what does a negative $\triangle H$ imply?

Answer: Exothermic process. Negative enthalpy means heat is released to the surroundings.

Flashcard 39: State the sign of $\triangle G$ for a spontaneous dissolution.

Answer: $\triangle G < 0$ . Negative free energy indicates a thermodynamically favorable process.

Flashcard 40: Identify the type of dissolution with $\triangle S > 0$ and $\triangle H < 0$ .

Answer: Spontaneous dissolution. Both favorable enthalpy and entropy make $\triangle G$ negative at all temperatures.

Flashcard 41: Identify the term for the heat change during dissolution.

Answer: Enthalpy change ( $\triangle H$ ). Enthalpy measures the heat absorbed or released during the process.

AP Chemistry Flashcards: Free Energy Of Dissolution

Free Energy Of Dissolution

What this deck covers

How to use these flashcards

All flashcards

Flashcard 1: Calculate △G\triangle G△G given △H=10 kJ/mol\triangle H = 10 \text{ kJ/mol}△H=10 kJ/mol, T=298 KT = 298 \text{ K}T=298 K, △S=50 J/mol\cdotpK\triangle S = 50 \text{ J/mol·K}△S=50 J/mol\cdotpK.

Flashcard 2: Which quantity becomes zero at the dissolution equilibrium point?

Flashcard 3: What is the primary driver of dissolution for ionic solids in water?

Flashcard 4: Calculate △G\triangle G△G with △H=20 kJ/mol\triangle H = 20 \text{ kJ/mol}△H=20 kJ/mol, T=350 KT = 350 \text{ K}T=350 K, △S=70 J/mol\cdotpK\triangle S = 70 \text{ J/mol·K}△S=70 J/mol\cdotpK.

Flashcard 5: Which parameter is zero for a process at equilibrium?

Flashcard 6: Determine the spontaneity: △H=5 kJ/mol\triangle H = 5 \text{ kJ/mol}△H=5 kJ/mol, T=298 KT = 298 \text{ K}T=298 K, △S=30 J/mol\cdotpK\triangle S = 30 \text{ J/mol·K}△S=30 J/mol\cdotpK.

Flashcard 7: What is the sign of △H\triangle H△H if dissolution absorbs heat?

Flashcard 8: What is indicated by a positive △G\triangle G△G in dissolution?

Flashcard 9: What determines the spontaneity of a dissolution process?

Flashcard 10: Determine the spontaneity: ΔH=5 kJ/mol\Delta H = 5 \text{ kJ/mol}ΔH=5 kJ/mol, T=298 KT = 298 \text{ K}T=298 K, ΔS=30 J/mol\cdotpK\Delta S = 30 \text{ J/mol·K}ΔS=30 J/mol\cdotpK.

Flashcard 11: What is the sign of △G\triangle G△G when △H<0\triangle H < 0△H<0 and △S>0\triangle S > 0△S>0?

Flashcard 12: Calculate △G\triangle G△G when △H=15 kJ/mol\triangle H = 15 \text{ kJ/mol}△H=15 kJ/mol, T=300 KT = 300 \text{ K}T=300 K, △S=60 J/mol\cdotpK\triangle S = 60 \text{ J/mol·K}△S=60 J/mol\cdotpK.

Flashcard 13: What does a positive △S\triangle S△S indicate about entropy in dissolution?

Flashcard 14: Determine the spontaneity: △H=5 kJ/mol\triangle H = 5 \text{ kJ/mol}△H=5 kJ/mol, T=298 KT = 298 \text{ K}T=298 K, △S=30 J/mol\cdotpK\triangle S = 30 \text{ J/mol·K}△S=30 J/mol\cdotpK.

Flashcard 15: State the condition for a dissolution to be spontaneous at all temperatures.

Flashcard 16: What is the sign of △G\triangle G△G when dissolution is at equilibrium?

Flashcard 17: Find the entropy change: △G=10 kJ/mol\triangle G = 10 \text{ kJ/mol}△G=10 kJ/mol, △H=15 kJ/mol\triangle H = 15 \text{ kJ/mol}△H=15 kJ/mol, T=298 KT = 298 \text{ K}T=298 K.

Flashcard 18: What does a positive △S\triangle S△S indicate about entropy in dissolution?

Flashcard 19: What is the relationship between △H\triangle H△H and △S\triangle S△S in spontaneous dissolution?

Flashcard 20: What is the unit of Gibbs free energy change?

Flashcard 21: State the effect on △G\triangle G△G if both △H\triangle H△H and △S\triangle S△S are positive.

Flashcard 22: Which factor affects the sign of △G\triangle G△G at constant pressure and temperature?

Flashcard 23: What effect does increased pressure have on gas solubility in liquids?

Flashcard 24: Identify the factor that primarily affects △S\triangle S△S in dissolution.

Flashcard 25: What does a negative △S\triangle S△S for dissolution indicate?

Flashcard 26: Identify the formula for entropy change.

Flashcard 27: What does a positive △S\triangle S△S indicate about entropy in dissolution?

Flashcard 28: Which parameter is affected by both enthalpy and entropy in dissolution?

Flashcard 29: Calculate △H\triangle H△H given △G=−3 kJ/mol\triangle G = -3 \text{ kJ/mol}△G=−3 kJ/mol, T=310 KT = 310 \text{ K}T=310 K, △S=80 J/mol\cdotpK\triangle S = 80 \text{ J/mol·K}△S=80 J/mol\cdotpK.

Flashcard 30: What type of process occurs when △G>0\triangle G > 0△G>0?

Flashcard 31: What is the significance of △G=0\triangle G = 0△G=0 in dissolution?

Flashcard 32: Calculate the enthalpy change: ΔG=−5 kJ/mol\Delta G = -5 \text{ kJ/mol}ΔG=−5 kJ/mol, T=298 KT = 298 \text{ K}T=298 K, ΔS=20 J/mol\cdotpK\Delta S = 20 \text{ J/mol·K}ΔS=20 J/mol\cdotpK.

Flashcard 33: Determine the spontaneity: △H=5 kJ/mol\triangle H = 5 \text{ kJ/mol}△H=5 kJ/mol, T=298 KT = 298 \text{ K}T=298 K, △S=30 J/mol\cdotpK\triangle S = 30 \text{ J/mol·K}△S=30 J/mol\cdotpK.

Flashcard 34: What is the effect of increasing temperature on an exothermic dissolution?

Flashcard 35: Which variable increases the dissolution rate in endothermic reactions?

Flashcard 36: How does the dissolution of a gas in a liquid typically affect ΔS\Delta SΔS?

Flashcard 37: What is the formula for Gibbs free energy change?

Flashcard 38: In dissolution, what does a negative △H\triangle H△H imply?

Flashcard 39: State the sign of △G\triangle G△G for a spontaneous dissolution.

Flashcard 40: Identify the type of dissolution with △S>0\triangle S > 0△S>0 and △H<0\triangle H < 0△H<0.

Flashcard 41: Identify the term for the heat change during dissolution.

Flashcard 1: Calculate $\triangle G$ given $\triangle H = 10 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 50 \text{ J/mol·K}$ .

Flashcard 4: Calculate $\triangle G$ with $\triangle H = 20 \text{ kJ/mol}$ , $T = 350 \text{ K}$ , $\triangle S = 70 \text{ J/mol·K}$ .

Flashcard 6: Determine the spontaneity: $\triangle H = 5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 30 \text{ J/mol·K}$ .

Flashcard 7: What is the sign of $\triangle H$ if dissolution absorbs heat?

Flashcard 8: What is indicated by a positive $\triangle G$ in dissolution?

Flashcard 10: Determine the spontaneity: $\Delta H = 5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\Delta S = 30 \text{ J/mol·K}$ .

Flashcard 11: What is the sign of $\triangle G$ when $\triangle H < 0$ and $\triangle S > 0$ ?

Flashcard 12: Calculate $\triangle G$ when $\triangle H = 15 \text{ kJ/mol}$ , $T = 300 \text{ K}$ , $\triangle S = 60 \text{ J/mol·K}$ .

Flashcard 13: What does a positive $\triangle S$ indicate about entropy in dissolution?

Flashcard 14: Determine the spontaneity: $\triangle H = 5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 30 \text{ J/mol·K}$ .

Flashcard 16: What is the sign of $\triangle G$ when dissolution is at equilibrium?

Flashcard 17: Find the entropy change: $\triangle G = 10 \text{ kJ/mol}$ , $\triangle H = 15 \text{ kJ/mol}$ , $T = 298 \text{ K}$ .

Flashcard 18: What does a positive $\triangle S$ indicate about entropy in dissolution?

Flashcard 19: What is the relationship between $\triangle H$ and $\triangle S$ in spontaneous dissolution?

Flashcard 21: State the effect on $\triangle G$ if both $\triangle H$ and $\triangle S$ are positive.

Flashcard 22: Which factor affects the sign of $\triangle G$ at constant pressure and temperature?

Flashcard 24: Identify the factor that primarily affects $\triangle S$ in dissolution.

Flashcard 25: What does a negative $\triangle S$ for dissolution indicate?

Flashcard 27: What does a positive $\triangle S$ indicate about entropy in dissolution?

Flashcard 29: Calculate $\triangle H$ given $\triangle G = -3 \text{ kJ/mol}$ , $T = 310 \text{ K}$ , $\triangle S = 80 \text{ J/mol·K}$ .

Flashcard 30: What type of process occurs when $\triangle G > 0$ ?

Flashcard 31: What is the significance of $\triangle G = 0$ in dissolution?

Flashcard 32: Calculate the enthalpy change: $\Delta G = -5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\Delta S = 20 \text{ J/mol·K}$ .

Flashcard 33: Determine the spontaneity: $\triangle H = 5 \text{ kJ/mol}$ , $T = 298 \text{ K}$ , $\triangle S = 30 \text{ J/mol·K}$ .

Flashcard 36: How does the dissolution of a gas in a liquid typically affect $\Delta S$ ?

Flashcard 38: In dissolution, what does a negative $\triangle H$ imply?

Flashcard 39: State the sign of $\triangle G$ for a spontaneous dissolution.

Flashcard 40: Identify the type of dissolution with $\triangle S > 0$ and $\triangle H < 0$ .