Podcast
Questions and Answers
What does it mean when the reaction quotient, $Q_c$, is less than the equilibrium constant, $K_c$?
What does it mean when the reaction quotient, $Q_c$, is less than the equilibrium constant, $K_c$?
- The reaction will shift to the left to reach equilibrium.
- The reaction will not proceed in either direction.
- The reaction is at equilibrium.
- The reaction will shift to the right to reach equilibrium. (correct)
What effect does increasing the temperature have on an exothermic reaction at equilibrium?
What effect does increasing the temperature have on an exothermic reaction at equilibrium?
- The equilibrium will shift to the right, favoring the formation of products.
- The equilibrium will shift to the left, favoring the formation of reactants. (correct)
- The equilibrium will not be affected.
- The equilibrium will shift in an unpredictable direction.
Consider the following reaction: $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$. If the pressure is increased, what will happen to the equilibrium?
Consider the following reaction: $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$. If the pressure is increased, what will happen to the equilibrium?
- The equilibrium will shift to the left, favoring the formation of nitrogen and hydrogen.
- The equilibrium will not be affected.
- The equilibrium will shift to the right, favoring the formation of ammonia. (correct)
- The equilibrium will shift in an unpredictable direction.
Which of the following changes will NOT affect the equilibrium position of a reaction?
Which of the following changes will NOT affect the equilibrium position of a reaction?
What is the correct expression for the equilibrium constant, $K_c$, for the reaction $2NO_2(g) \rightleftharpoons N_2O_4(g)$?
What is the correct expression for the equilibrium constant, $K_c$, for the reaction $2NO_2(g) \rightleftharpoons N_2O_4(g)$?
A solution contains $Ag^+$, $Ba^{2+}$, and $Cl^-$ ions. If the solution is saturated, what is the precipitate that will form?
A solution contains $Ag^+$, $Ba^{2+}$, and $Cl^-$ ions. If the solution is saturated, what is the precipitate that will form?
What is the relationship between $K_a$, $K_b$, and $K_w$ for a conjugate acid-base pair?
What is the relationship between $K_a$, $K_b$, and $K_w$ for a conjugate acid-base pair?
What is the $pH$ of a $0.10 M$ solution of a weak acid with a $K_a = 10^{-5}$? (Assume the change in concentration, 'x', is negligible).
What is the $pH$ of a $0.10 M$ solution of a weak acid with a $K_a = 10^{-5}$? (Assume the change in concentration, 'x', is negligible).
The solubility product constant, $K_{sp}$, for $CaF_2$ is $3.9 \times10^{-11}$. What is the molar solubility of $CaF_2$ in pure water?
The solubility product constant, $K_{sp}$, for $CaF_2$ is $3.9 \times10^{-11}$. What is the molar solubility of $CaF_2$ in pure water?
Consider the following equilibrium reaction: $A(g) + B(g) \rightleftharpoons 2C(g)$. If the initial concentrations of $A$ and $B$ are both $0.10 M$ and the equilibrium concentration of $C$ is found to be $0.05 M$, what is the value of $K_c$?
Consider the following equilibrium reaction: $A(g) + B(g) \rightleftharpoons 2C(g)$. If the initial concentrations of $A$ and $B$ are both $0.10 M$ and the equilibrium concentration of $C$ is found to be $0.05 M$, what is the value of $K_c$?
Flashcards
Dynamic Equilibrium
Dynamic Equilibrium
The state where the rate of the forward reaction equals the rate of the reverse reaction, resulting in no net change in concentrations of reactants and products.
Equilibrium Constant (Kc)
Equilibrium Constant (Kc)
A constant that expresses the ratio of product concentrations to reactant concentrations at equilibrium, each raised to the power of their stoichiometric coefficients.
Le Chatelier's Principle
Le Chatelier's Principle
A principle stating that if a system at equilibrium is disturbed by a change in conditions, the system will shift to relieve the stress and re-establish equilibrium.
Le Chatelier's Principle: Concentration Change (Adding Reactant)
Le Chatelier's Principle: Concentration Change (Adding Reactant)
Signup and view all the flashcards
Le Chatelier's Principle: Pressure Change
Le Chatelier's Principle: Pressure Change
Signup and view all the flashcards
Le Chatelier's Principle: Temperature Change (Endothermic)
Le Chatelier's Principle: Temperature Change (Endothermic)
Signup and view all the flashcards
Reaction Quotient (Qc)
Reaction Quotient (Qc)
Signup and view all the flashcards
Solubility Product Constant (Ksp)
Solubility Product Constant (Ksp)
Signup and view all the flashcards
Ion-Product Constant for Water (Kw)
Ion-Product Constant for Water (Kw)
Signup and view all the flashcards
Acid Dissociation Constant (Ka)
Acid Dissociation Constant (Ka)
Signup and view all the flashcards
Study Notes
Dynamic Equilibrium
- Occurs when the rate of the forward reaction equals the rate of the reverse reaction.
- Example: aA + bB ⇌ cC + dD
Equilibrium Constant (Kc)
- Ratio of product concentrations to reactant concentrations at equilibrium, raised to the power of their coefficients.
- Formula: Kc = [products] / [reactants]
- Magnitude indicates whether the reaction favors products or reactants.
Le Chatelier's Principle
- If a system at equilibrium is disturbed, it shifts to counteract the disturbance.
- Changes in concentration, pressure (volume), and temperature affect equilibrium position.
- Concentration: Increasing reactants shifts right; increasing products shifts left.
- Pressure: Increasing pressure (decreasing volume) shifts the reaction towards the side with fewer moles of gas.
- Temperature: Exothermic reactions shift left with increased temperature; endothermic reactions shift right.
Calculating Qc
- Reaction quotient to predict equilibrium shift
- Formula: Qc = [products] / [reactants]
- Compare Qc to Kc:
- Qc < Kc: Reaction shifts right (must form products)
- Qc > Kc: Reaction shifts left (must form reactants)
- Qc = Kc : Reaction is at equilibrium
Calculating Ksp
- Solubility product constant for sparingly soluble salts.
- Formula: Ksp = [cation]^a [anion]^b (e.g., PbCl2(s)⇌Pb2+(aq)+2Cl−(aq))
- Examples involving the equilibrium of precipitate formation, and how to solve for unknown concentrations.
Calculating Qsp
- Ion product of a solution containing one or more ionic species.
- Formula: Qsp = [cation]a [anion]b
- Compare Qsp and Ksp:
- Qsp < Ksp: No precipitate forms
- Qsp > Ksp: Precipitate forms
- Qsp = Ksp: Solution is saturated
Kw Calculations
- Water's ion product constant at 25°C.
- Kw = [H3O+][OH−] = 1.0 × 10⁻¹⁴
Acid/Base Dissociation Constant
- Key formulas:
- Ka = [H3O+][A⁻] / [HA]
- Kb = [OH⁻][HB⁺] / [B]
- Ka × Kb = Kw
- Calculating % dissociation: ([H3O⁺] / [acid initial]) × 100
- pH + pOH = 14, and the relationship between pH and [H3O⁺] (p and log)
Approximating
- When Kc value (or Ka, or Kb) is significantly smaller than initial concentrations.
- If initial concentration ≥ 500 × Kc Value, ignore x or the change in concentration
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
