Calculating Equilibrium Concentrations - AP Chemistry
Card 1 of 30
Find $K_c$ for $A \rightleftharpoons 2B$ if $[A] = 1M$, $[B] = 0.5M$ at equilibrium.
Find $K_c$ for $A \rightleftharpoons 2B$ if $[A] = 1M$, $[B] = 0.5M$ at equilibrium.
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$K_c = \frac{0.5^2}{1}$. $K_c = \frac{[B]^2}{[A]} = \frac{0.5^2}{1} = 0.25$.
$K_c = \frac{0.5^2}{1}$. $K_c = \frac{[B]^2}{[A]} = \frac{0.5^2}{1} = 0.25$.
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For the reaction $2NO(g) + O_2(g) \rightleftharpoons 2NO_2(g)$, what is the $K_p$ expression?
For the reaction $2NO(g) + O_2(g) \rightleftharpoons 2NO_2(g)$, what is the $K_p$ expression?
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$K_p = \frac{P_{NO_2}^2}{P_{NO}^2 P_{O_2}}$. Products over reactants using partial pressures, raised to coefficients.
$K_p = \frac{P_{NO_2}^2}{P_{NO}^2 P_{O_2}}$. Products over reactants using partial pressures, raised to coefficients.
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How does a decrease in the concentration of $O_2$ affect equilibrium in $2SO_2 + O_2 \rightleftharpoons 2SO_3$?
How does a decrease in the concentration of $O_2$ affect equilibrium in $2SO_2 + O_2 \rightleftharpoons 2SO_3$?
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Shifts left. Removing reactant shifts equilibrium to replace it via reverse reaction.
Shifts left. Removing reactant shifts equilibrium to replace it via reverse reaction.
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State the effect of adding a reactant on the equilibrium position.
State the effect of adding a reactant on the equilibrium position.
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Shifts right to form more products. Le Chatelier's principle: system responds by consuming the added reactant.
Shifts right to form more products. Le Chatelier's principle: system responds by consuming the added reactant.
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For the endothermic reaction $A \rightleftharpoons B$, what is the effect of increasing temperature?
For the endothermic reaction $A \rightleftharpoons B$, what is the effect of increasing temperature?
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Shifts towards $B$. Higher temperature favors endothermic reactions (heat-absorbing direction).
Shifts towards $B$. Higher temperature favors endothermic reactions (heat-absorbing direction).
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What is the effect of adding a product on the position of equilibrium?
What is the effect of adding a product on the position of equilibrium?
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Shifts left to form more reactants. Le Chatelier's principle: system responds by consuming the added product.
Shifts left to form more reactants. Le Chatelier's principle: system responds by consuming the added product.
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For $2NO_2(g) \rightleftharpoons N_2O_4(g)$, what happens to $K_c$ if temperature is increased?
For $2NO_2(g) \rightleftharpoons N_2O_4(g)$, what happens to $K_c$ if temperature is increased?
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$K_c$ decreases. Higher temperature opposes exothermic reactions, decreasing $K_c$.
$K_c$ decreases. Higher temperature opposes exothermic reactions, decreasing $K_c$.
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What is the equilibrium constant expression for $2H_2O_2(aq) \rightleftharpoons 2H_2O(l) + O_2(g)$?
What is the equilibrium constant expression for $2H_2O_2(aq) \rightleftharpoons 2H_2O(l) + O_2(g)$?
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$K_c = [O_2]$. Liquids are excluded from equilibrium expressions, only gases included.
$K_c = [O_2]$. Liquids are excluded from equilibrium expressions, only gases included.
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What is the effect of pressure decrease on equilibrium of $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$?
What is the effect of pressure decrease on equilibrium of $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$?
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Shifts left. Lower pressure favors the side with more gas molecules (4 vs 2).
Shifts left. Lower pressure favors the side with more gas molecules (4 vs 2).
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Calculate $K_c$ for $H_2 + I_2 \rightleftharpoons 2HI$ with $[H_2] = 1M$, $[I_2] = 1M$, $[HI] = 2M$.
Calculate $K_c$ for $H_2 + I_2 \rightleftharpoons 2HI$ with $[H_2] = 1M$, $[I_2] = 1M$, $[HI] = 2M$.
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$K_c = \frac{4}{1}$. $K_c = \frac{[HI]^2}{[H_2][I_2]} = \frac{2^2}{1 \times 1} = 4$.
$K_c = \frac{4}{1}$. $K_c = \frac{[HI]^2}{[H_2][I_2]} = \frac{2^2}{1 \times 1} = 4$.
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What is the equilibrium expression for $H_2(g) + S(s) \rightleftharpoons H_2S(g)$?
What is the equilibrium expression for $H_2(g) + S(s) \rightleftharpoons H_2S(g)$?
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$K_c = [H_2S]$. Solids are excluded from equilibrium expressions, only gases included.
$K_c = [H_2S]$. Solids are excluded from equilibrium expressions, only gases included.
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For the reaction $PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$, what is the effect of decreasing temperature?
For the reaction $PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$, what is the effect of decreasing temperature?
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Shifts towards $PCl_5$. Lower temperature favors the exothermic direction (heat-producing side).
Shifts towards $PCl_5$. Lower temperature favors the exothermic direction (heat-producing side).
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What is the effect of increasing temperature on the equilibrium position of an exothermic reaction?
What is the effect of increasing temperature on the equilibrium position of an exothermic reaction?
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Shifts towards reactants. Higher temperature opposes exothermic reactions, favoring the reverse direction.
Shifts towards reactants. Higher temperature opposes exothermic reactions, favoring the reverse direction.
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For $N_2O_4(g) \rightleftharpoons 2NO_2(g)$, how does increasing pressure affect equilibrium?
For $N_2O_4(g) \rightleftharpoons 2NO_2(g)$, how does increasing pressure affect equilibrium?
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Shifts towards $N_2O_4$. Higher pressure favors the side with fewer gas molecules (1 vs 2).
Shifts towards $N_2O_4$. Higher pressure favors the side with fewer gas molecules (1 vs 2).
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Identify the equilibrium expression for $CO(g) + Cl_2(g) \rightleftharpoons COCl_2(g)$.
Identify the equilibrium expression for $CO(g) + Cl_2(g) \rightleftharpoons COCl_2(g)$.
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$K_c = \frac{[COCl_2]}{[CO][Cl_2]}$. Products over reactants, each raised to their stoichiometric coefficients.
$K_c = \frac{[COCl_2]}{[CO][Cl_2]}$. Products over reactants, each raised to their stoichiometric coefficients.
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If $K_c = 1.5$ for the reaction $A \rightleftharpoons B$, what is the value of $K_c$ for $B \rightleftharpoons A$?
If $K_c = 1.5$ for the reaction $A \rightleftharpoons B$, what is the value of $K_c$ for $B \rightleftharpoons A$?
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$K_c = \frac{1}{1.5}$. For the reverse reaction, $K_c$ becomes the reciprocal of the original.
$K_c = \frac{1}{1.5}$. For the reverse reaction, $K_c$ becomes the reciprocal of the original.
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For the reaction $H_2(g) + I_2(g) \rightleftharpoons 2HI(g)$, find $K_c$ if $[HI] = 2M$, $[H_2] = 1M$, $[I_2] = 1M$.
For the reaction $H_2(g) + I_2(g) \rightleftharpoons 2HI(g)$, find $K_c$ if $[HI] = 2M$, $[H_2] = 1M$, $[I_2] = 1M$.
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$K_c = 4$. $K_c = \frac{[HI]^2}{[H_2][I_2]} = \frac{2^2}{1 \times 1} = 4$.
$K_c = 4$. $K_c = \frac{[HI]^2}{[H_2][I_2]} = \frac{2^2}{1 \times 1} = 4$.
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State the $K_c$ expression for the reaction $C_2H_4(g) + H_2(g) \rightleftharpoons C_2H_6(g)$.
State the $K_c$ expression for the reaction $C_2H_4(g) + H_2(g) \rightleftharpoons C_2H_6(g)$.
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$K_c = \frac{[C_2H_6]}{[C_2H_4][H_2]}$. Products over reactants, each raised to their stoichiometric coefficients.
$K_c = \frac{[C_2H_6]}{[C_2H_4][H_2]}$. Products over reactants, each raised to their stoichiometric coefficients.
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What happens to $K_c$ of an exothermic reaction when temperature increases?
What happens to $K_c$ of an exothermic reaction when temperature increases?
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$K_c$ decreases. Higher temperature opposes exothermic reactions, decreasing $K_c$.
$K_c$ decreases. Higher temperature opposes exothermic reactions, decreasing $K_c$.
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For the reaction $C(s) + CO_2(g) \rightleftharpoons 2CO(g)$, write the $K_c$ expression.
For the reaction $C(s) + CO_2(g) \rightleftharpoons 2CO(g)$, write the $K_c$ expression.
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$K_c = [CO]^2/[CO_2]$. Solid carbon is excluded, only gaseous species are included.
$K_c = [CO]^2/[CO_2]$. Solid carbon is excluded, only gaseous species are included.
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Find $K_c$ for the reaction $2A \rightleftharpoons B + C$ if $[A] = 0.5M$, $[B] = 1M$, $[C] = 1M$.
Find $K_c$ for the reaction $2A \rightleftharpoons B + C$ if $[A] = 0.5M$, $[B] = 1M$, $[C] = 1M$.
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$K_c = \frac{1 \times 1}{0.5^2}$. $K_c = \frac{[B][C]}{[A]^2} = \frac{1 \times 1}{0.5^2} = 4$.
$K_c = \frac{1 \times 1}{0.5^2}$. $K_c = \frac{[B][C]}{[A]^2} = \frac{1 \times 1}{0.5^2} = 4$.
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Identify the equilibrium expression for the reaction $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$.
Identify the equilibrium expression for the reaction $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$.
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$K_c = \frac{[NH_3]^2}{[N_2][H_2]^3}$. Products over reactants, each raised to their stoichiometric coefficients.
$K_c = \frac{[NH_3]^2}{[N_2][H_2]^3}$. Products over reactants, each raised to their stoichiometric coefficients.
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Given $K_c = 10$ for $A \rightleftharpoons B$, find $K_c$ for $2A \rightleftharpoons 2B$.
Given $K_c = 10$ for $A \rightleftharpoons B$, find $K_c$ for $2A \rightleftharpoons 2B$.
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$K_c = 10^2$. When reaction is doubled, equilibrium constant is squared.
$K_c = 10^2$. When reaction is doubled, equilibrium constant is squared.
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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 in numerator raised to their coefficients, reactants in denominator.
$K_c = \frac{[C]^c[D]^d}{[A]^a[B]^b}$. Products in numerator raised to their coefficients, reactants in denominator.
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What happens to the equilibrium position when pressure is increased for the reaction $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$?
What happens to the equilibrium position when pressure is increased for the reaction $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$?
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Shifts towards $NH_3$. Higher pressure favors the side with fewer gas molecules (2 vs 4).
Shifts towards $NH_3$. Higher pressure favors the side with fewer gas molecules (2 vs 4).
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What is the effect of adding an inert gas at constant volume on the equilibrium of a reaction?
What is the effect of adding an inert gas at constant volume on the equilibrium of a reaction?
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No effect. Inert gas doesn't participate and doesn't change partial pressures.
No effect. Inert gas doesn't participate and doesn't change partial pressures.
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For the reaction $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$, what is the expression for $K_p$?
For the reaction $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$, what is the expression for $K_p$?
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$K_p = \frac{P_{SO_3}^2}{P_{SO_2}^2 P_{O_2}}$. Products over reactants using partial pressures, raised to coefficients.
$K_p = \frac{P_{SO_3}^2}{P_{SO_2}^2 P_{O_2}}$. Products over reactants using partial pressures, raised to coefficients.
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What is the effect of a catalyst on the equilibrium constant $K$?
What is the effect of a catalyst on the equilibrium constant $K$?
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No effect. Catalysts only affect reaction rate, not equilibrium position or $K$.
No effect. Catalysts only affect reaction rate, not equilibrium position or $K$.
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For the reaction $CH_4(g) + 2O_2(g) \rightleftharpoons CO_2(g) + 2H_2O(g)$, write the $K_c$ expression.
For the reaction $CH_4(g) + 2O_2(g) \rightleftharpoons CO_2(g) + 2H_2O(g)$, write the $K_c$ expression.
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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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Determine the equilibrium constant $K_c$ for the reaction $2NO_2(g) \rightleftharpoons N_2O_4(g)$ given $[NO_2] = 0.5M$, $[N_2O_4] = 0.2M$.
Determine the equilibrium constant $K_c$ for the reaction $2NO_2(g) \rightleftharpoons N_2O_4(g)$ given $[NO_2] = 0.5M$, $[N_2O_4] = 0.2M$.
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$K_c = 0.8$. $K_c = \frac{[N_2O_4]}{[NO_2]^2} = \frac{0.2}{0.5^2} = 0.8$.
$K_c = 0.8$. $K_c = \frac{[N_2O_4]}{[NO_2]^2} = \frac{0.2}{0.5^2} = 0.8$.
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