Magnitude of the Equilibrium Constant - AP Chemistry
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What is true about the equilibrium constant when a reaction reaches equilibrium?
What is true about the equilibrium constant when a reaction reaches equilibrium?
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The rate of the forward and reverse reactions are equal. At equilibrium, the equilibrium constant value remains constant.
The rate of the forward and reverse reactions are equal. At equilibrium, the equilibrium constant value remains constant.
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What is the expression for the equilibrium constant $K_c$ for the reaction $aA + bB \rightleftharpoons cC + dD$?
What is the expression for the equilibrium constant $K_c$ for the reaction $aA + bB \rightleftharpoons cC + dD$?
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$K_c = \frac{[C]^c[D]^d}{[A]^a[B]^b}$. Products raised to coefficients over reactants raised to coefficients.
$K_c = \frac{[C]^c[D]^d}{[A]^a[B]^b}$. Products raised to coefficients over reactants raised to coefficients.
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If the equilibrium constant $K$ for a reaction is $0.01$, what does this suggest?
If the equilibrium constant $K$ for a reaction is $0.01$, what does this suggest?
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The reaction is reactant-favored. $K < 1$ means reactants predominate at equilibrium.
The reaction is reactant-favored. $K < 1$ means reactants predominate at equilibrium.
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What does a large $K_c$ value indicate about the position of equilibrium?
What does a large $K_c$ value indicate about the position of equilibrium?
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The equilibrium favors products. Large $K$ means products are more abundant at equilibrium.
The equilibrium favors products. Large $K$ means products are more abundant at equilibrium.
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For $N_2(g) + O_2(g) \rightleftharpoons 2NO(g)$, write the $K_c$ expression.
For $N_2(g) + O_2(g) \rightleftharpoons 2NO(g)$, write the $K_c$ expression.
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$K_c = \frac{[NO]^2}{[N_2][O_2]}$. Products over reactants, raised to stoichiometric coefficients.
$K_c = \frac{[NO]^2}{[N_2][O_2]}$. Products over reactants, raised to stoichiometric coefficients.
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What is the effect on $K_c$ if the temperature increases for an endothermic reaction?
What is the effect on $K_c$ if the temperature increases for an endothermic reaction?
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$K_c$ increases. Higher temperature favors endothermic direction (products).
$K_c$ increases. Higher temperature favors endothermic direction (products).
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For the reaction $2A(g) \rightleftharpoons B(g) + C(g)$, write the $K_p$ expression.
For the reaction $2A(g) \rightleftharpoons B(g) + C(g)$, write the $K_p$ expression.
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$K_p = \frac{P_B P_C}{P_A^2}$. Partial pressures of products over reactants, raised to coefficients.
$K_p = \frac{P_B P_C}{P_A^2}$. Partial pressures of products over reactants, raised to coefficients.
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What does a small $K_c$ value indicate about the position of equilibrium?
What does a small $K_c$ value indicate about the position of equilibrium?
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The equilibrium favors reactants. Small $K$ means reactants are more abundant at equilibrium.
The equilibrium favors reactants. Small $K$ means reactants are more abundant at equilibrium.
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Determine the $K_c$ expression for $2NO_2(g) \rightleftharpoons N_2O_4(g)$.
Determine the $K_c$ expression for $2NO_2(g) \rightleftharpoons N_2O_4(g)$.
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$K_c = \frac{[N_2O_4]}{[NO_2]^2}$. Products over reactants, with each raised to stoichiometric coefficients.
$K_c = \frac{[N_2O_4]}{[NO_2]^2}$. Products over reactants, with each raised to stoichiometric coefficients.
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Identify the equilibrium constant expression $K_p$ for the reaction $aA(g) + bB(g) \rightleftharpoons cC(g) + dD(g)$.
Identify the equilibrium constant expression $K_p$ for the reaction $aA(g) + bB(g) \rightleftharpoons cC(g) + dD(g)$.
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$K_p = \frac{(P_C)^c(P_D)^d}{(P_A)^a(P_B)^b}$. Uses partial pressures instead of concentrations in the expression.
$K_p = \frac{(P_C)^c(P_D)^d}{(P_A)^a(P_B)^b}$. Uses partial pressures instead of concentrations in the expression.
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State the relationship between $K_c$ and the rate constants $k_f$ and $k_r$ for a reaction.
State the relationship between $K_c$ and the rate constants $k_f$ and $k_r$ for a reaction.
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$K_c = \frac{k_f}{k_r}$. Ratio of forward to reverse rate constants equals equilibrium constant.
$K_c = \frac{k_f}{k_r}$. Ratio of forward to reverse rate constants equals equilibrium constant.
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What is the effect on $K_c$ if the temperature decreases for an endothermic reaction?
What is the effect on $K_c$ if the temperature decreases for an endothermic reaction?
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$K_c$ decreases. Lower temperature shifts endothermic equilibrium toward reactants.
$K_c$ decreases. Lower temperature shifts endothermic equilibrium toward reactants.
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What is the equilibrium constant $K_c$ for the reverse reaction if the forward reaction has $K_c = 10$?
What is the equilibrium constant $K_c$ for the reverse reaction if the forward reaction has $K_c = 10$?
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$K_c = 0.1$. Reverse reaction constant equals $1/K_{forward}$.
$K_c = 0.1$. Reverse reaction constant equals $1/K_{forward}$.
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If $K_c = 1000$ for a reaction, is it product or reactant favored?
If $K_c = 1000$ for a reaction, is it product or reactant favored?
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Product favored. $K > 1$ indicates products are favored at equilibrium.
Product favored. $K > 1$ indicates products are favored at equilibrium.
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For the equilibrium $PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$, write the $K_c$ expression.
For the equilibrium $PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$, write the $K_c$ expression.
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$K_c = \frac{[PCl_3][Cl_2]}{[PCl_5]}$. Products over reactants, raised to stoichiometric coefficients.
$K_c = \frac{[PCl_3][Cl_2]}{[PCl_5]}$. Products over reactants, raised to stoichiometric coefficients.
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Determine the $K_c$ expression for $CH_4(g) + 2O_2(g) \rightleftharpoons CO_2(g) + 2H_2O(g)$.
Determine the $K_c$ expression for $CH_4(g) + 2O_2(g) \rightleftharpoons CO_2(g) + 2H_2O(g)$.
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$K_c = \frac{[CO_2][H_2O]^2}{[CH_4][O_2]^2}$. Products over reactants, each raised to their stoichiometric coefficients.
$K_c = \frac{[CO_2][H_2O]^2}{[CH_4][O_2]^2}$. Products over reactants, each raised to their stoichiometric coefficients.
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How does $K_c$ change if a catalyst is added to a reaction?
How does $K_c$ change if a catalyst is added to a reaction?
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$K_c$ remains unchanged. Catalysts affect reaction rate but not equilibrium position.
$K_c$ remains unchanged. Catalysts affect reaction rate but not equilibrium position.
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Predict how $K_c$ will shift if pressure is increased for $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$.
Predict how $K_c$ will shift if pressure is increased for $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$.
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$K_c$ does not change. Equilibrium constant depends only on temperature, not pressure.
$K_c$ does not change. Equilibrium constant depends only on temperature, not pressure.
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What is the expression for $K_c$ for the decomposition of $H_2O(g)$ into $H_2(g)$ and $O_2(g)$?
What is the expression for $K_c$ for the decomposition of $H_2O(g)$ into $H_2(g)$ and $O_2(g)$?
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$K_c = \frac{[H_2]^2[O_2]}{[H_2O]^2}$. Decomposition: $2H_2O(g) \rightleftharpoons 2H_2(g) + O_2(g)$.
$K_c = \frac{[H_2]^2[O_2]}{[H_2O]^2}$. Decomposition: $2H_2O(g) \rightleftharpoons 2H_2(g) + O_2(g)$.
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What is the equilibrium expression for $K_c$ for the reaction $2SO_3(g) \rightleftharpoons 2SO_2(g) + O_2(g)$?
What is the equilibrium expression for $K_c$ for the reaction $2SO_3(g) \rightleftharpoons 2SO_2(g) + O_2(g)$?
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$K_c = \frac{[SO_2]^2[O_2]}{[SO_3]^2}$. Products over reactants, raised to stoichiometric coefficients.
$K_c = \frac{[SO_2]^2[O_2]}{[SO_3]^2}$. Products over reactants, raised to stoichiometric coefficients.
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For $2NO(g) + O_2(g) \rightleftharpoons 2NO_2(g)$, provide the $K_c$ expression.
For $2NO(g) + O_2(g) \rightleftharpoons 2NO_2(g)$, provide the $K_c$ expression.
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$K_c = \frac{[NO_2]^2}{[NO]^2[O_2]}$. Products over reactants, raised to stoichiometric coefficients.
$K_c = \frac{[NO_2]^2}{[NO]^2[O_2]}$. Products over reactants, raised to stoichiometric coefficients.
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For $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$, write the $K_c$ expression.
For $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$, write the $K_c$ expression.
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$K_c = \frac{[SO_3]^2}{[SO_2]^2[O_2]}$. Products over reactants, raised to stoichiometric coefficients.
$K_c = \frac{[SO_3]^2}{[SO_2]^2[O_2]}$. Products over reactants, raised to stoichiometric coefficients.
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Calculate $K_p$ from $K_c = 50$ for $H_2(g) + I_2(g) \rightleftharpoons 2HI(g)$ at 300 K.
Calculate $K_p$ from $K_c = 50$ for $H_2(g) + I_2(g) \rightleftharpoons 2HI(g)$ at 300 K.
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$K_p = 50$. $\Delta n = 0$, so $K_p = K_c$.
$K_p = 50$. $\Delta n = 0$, so $K_p = K_c$.
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What will happen to $K_c$ if the equation coefficients are doubled?
What will happen to $K_c$ if the equation coefficients are doubled?
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$K_c$ is squared. When coefficients are multiplied by $n$, $K$ is raised to the $n$th power.
$K_c$ is squared. When coefficients are multiplied by $n$, $K$ is raised to the $n$th power.
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What happens to $K_c$ if the equation is reversed?
What happens to $K_c$ if the equation is reversed?
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$K_c$ becomes $1/K_c$. Reversing the equation inverts the equilibrium constant.
$K_c$ becomes $1/K_c$. Reversing the equation inverts the equilibrium constant.
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What is the effect on $K_p$ if the temperature increases for an exothermic reaction?
What is the effect on $K_p$ if the temperature increases for an exothermic reaction?
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$K_p$ decreases. Le Chatelier's principle: heat shifts equilibrium toward reactants.
$K_p$ decreases. Le Chatelier's principle: heat shifts equilibrium toward reactants.
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If the equilibrium constant $K$ for a reaction is $0.01$, what does this suggest?
If the equilibrium constant $K$ for a reaction is $0.01$, what does this suggest?
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The reaction is reactant-favored. $K < 1$ means reactants predominate at equilibrium.
The reaction is reactant-favored. $K < 1$ means reactants predominate at equilibrium.
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What is true about the equilibrium constant when a reaction reaches equilibrium?
What is true about the equilibrium constant when a reaction reaches equilibrium?
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The rate of the forward and reverse reactions are equal. At equilibrium, the equilibrium constant value remains constant.
The rate of the forward and reverse reactions are equal. At equilibrium, the equilibrium constant value remains constant.
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For the reaction $A \rightleftharpoons B$, if $K_c = 1$, what does this indicate?
For the reaction $A \rightleftharpoons B$, if $K_c = 1$, what does this indicate?
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The concentrations of products and reactants are equal. $K_c = 1$ means equal concentrations of A and B at equilibrium.
The concentrations of products and reactants are equal. $K_c = 1$ means equal concentrations of A and B at equilibrium.
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State how $K_c$ is affected by a change in concentration.
State how $K_c$ is affected by a change in concentration.
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$K_c$ is unaffected. Equilibrium constant is independent of concentration changes.
$K_c$ is unaffected. Equilibrium constant is independent of concentration changes.
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