Reaction Quotient and Equilibrium Constant - AP Chemistry
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For $CaCO_3(s)\rightleftharpoons CaO(s)+CO_2(g)$, what is the correct $K_p$ expression?
For $CaCO_3(s)\rightleftharpoons CaO(s)+CO_2(g)$, what is the correct $K_p$ expression?
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$K_p=P_{CO_2}$. Solids omitted; only gas pressure appears.
$K_p=P_{CO_2}$. Solids omitted; only gas pressure appears.
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What is $\Delta n_{gas}$ in $K_p=K_c(RT)^{\Delta n_{gas}}$ for $aA(g)\rightleftharpoons bB(g)$?
What is $\Delta n_{gas}$ in $K_p=K_c(RT)^{\Delta n_{gas}}$ for $aA(g)\rightleftharpoons bB(g)$?
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$\Delta n_{gas}=b-a$. Moles of gas products minus moles of gas reactants.
$\Delta n_{gas}=b-a$. Moles of gas products minus moles of gas reactants.
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What happens to $K$ if the balanced equation is reversed?
What happens to $K$ if the balanced equation is reversed?
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$K_{rev}=\frac{1}{K}$. Reversing flips the fraction.
$K_{rev}=\frac{1}{K}$. Reversing flips the fraction.
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What happens to $K$ if all coefficients in the balanced equation are multiplied by $n$?
What happens to $K$ if all coefficients in the balanced equation are multiplied by $n$?
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$K_{new}=K^n$. Each concentration term gets raised to the new coefficient.
$K_{new}=K^n$. Each concentration term gets raised to the new coefficient.
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For $2NO_2(g)\rightleftharpoons N_2O_4(g)$, what is the correct $Q_p$ expression?
For $2NO_2(g)\rightleftharpoons N_2O_4(g)$, what is the correct $Q_p$ expression?
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$Q_p=\frac{P_{N_2O_4}}{(P_{NO_2})^2}$. Products over reactants with stoichiometric exponents.
$Q_p=\frac{P_{N_2O_4}}{(P_{NO_2})^2}$. Products over reactants with stoichiometric exponents.
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If $K_c=2.0\times10^{4}$, which side is favored at equilibrium: reactants or products?
If $K_c=2.0\times10^{4}$, which side is favored at equilibrium: reactants or products?
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Products are favored. $K>>1$ means equilibrium lies far to the right.
Products are favored. $K>>1$ means equilibrium lies far to the right.
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If $K_c=5.0\times10^{-3}$, which side is favored at equilibrium: reactants or products?
If $K_c=5.0\times10^{-3}$, which side is favored at equilibrium: reactants or products?
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Reactants are favored. $K<<1$ means equilibrium lies far to the left.
Reactants are favored. $K<<1$ means equilibrium lies far to the left.
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For $H_2(g)+I_2(g)\rightleftharpoons 2HI(g)$, what is $\Delta n_{gas}$?
For $H_2(g)+I_2(g)\rightleftharpoons 2HI(g)$, what is $\Delta n_{gas}$?
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$\Delta n_{gas}=0$. 2 moles gas products minus 2 moles gas reactants.
$\Delta n_{gas}=0$. 2 moles gas products minus 2 moles gas reactants.
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For $H_2(g)+I_2(g)\rightleftharpoons 2HI(g)$, what is the relationship between $K_p$ and $K_c$?
For $H_2(g)+I_2(g)\rightleftharpoons 2HI(g)$, what is the relationship between $K_p$ and $K_c$?
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$K_p=K_c$. When $\Delta n_{gas}=0$, $(RT)^0=1$.
$K_p=K_c$. When $\Delta n_{gas}=0$, $(RT)^0=1$.
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Calculate $Q_c$ for $A\rightleftharpoons B$ if $[A]=0.50$ and $[B]=2.0$.
Calculate $Q_c$ for $A\rightleftharpoons B$ if $[A]=0.50$ and $[B]=2.0$.
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$Q_c=4.0$. $Q_c=\frac{[B]}{[A]}=\frac{2.0}{0.50}=4.0$
$Q_c=4.0$. $Q_c=\frac{[B]}{[A]}=\frac{2.0}{0.50}=4.0$
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Identify the shift for $A\rightleftharpoons B$ if $K_c=10$ and $Q_c=4$.
Identify the shift for $A\rightleftharpoons B$ if $K_c=10$ and $Q_c=4$.
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Shifts right (toward products). $Q<K$ means more products needed for equilibrium.
Shifts right (toward products). $Q<K$ means more products needed for equilibrium.
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What is the expression for $Q_c$ for $aA+bB\rightleftharpoons cC+dD$ using concentrations?
What is the expression for $Q_c$ for $aA+bB\rightleftharpoons cC+dD$ using concentrations?
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$Q_c=\frac{[C]^c[D]^d}{[A]^a[B]^b}$. Products over reactants, each raised to its coefficient.
$Q_c=\frac{[C]^c[D]^d}{[A]^a[B]^b}$. Products over reactants, each raised to its coefficient.
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What is the expression for $Q_p$ for $aA(g)+bB(g)\rightleftharpoons cC(g)+dD(g)$ using partial pressures?
What is the expression for $Q_p$ for $aA(g)+bB(g)\rightleftharpoons cC(g)+dD(g)$ using partial pressures?
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$Q_p=\frac{(P_C)^c(P_D)^d}{(P_A)^a(P_B)^b}$. Uses partial pressures instead of concentrations.
$Q_p=\frac{(P_C)^c(P_D)^d}{(P_A)^a(P_B)^b}$. Uses partial pressures instead of concentrations.
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What is the definition of $K$ in terms of $Q$ for a reaction at equilibrium?
What is the definition of $K$ in terms of $Q$ for a reaction at equilibrium?
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$K=Q$ at equilibrium. At equilibrium, reaction quotient equals equilibrium constant.
$K=Q$ at equilibrium. At equilibrium, reaction quotient equals equilibrium constant.
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Which species are omitted from $Q$ and $K$: pure solids, pure liquids, solutes, or gases?
Which species are omitted from $Q$ and $K$: pure solids, pure liquids, solutes, or gases?
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Pure solids and pure liquids are omitted. Their activities equal 1, so they don't affect the ratio.
Pure solids and pure liquids are omitted. Their activities equal 1, so they don't affect the ratio.
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What is the exponent on each term in $Q$ or $K$ relative to the balanced chemical equation?
What is the exponent on each term in $Q$ or $K$ relative to the balanced chemical equation?
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Each exponent equals its stoichiometric coefficient. Reflects how many moles participate in the reaction.
Each exponent equals its stoichiometric coefficient. Reflects how many moles participate in the reaction.
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Identify the correct comparison rule: if $Q<K$, which direction does the reaction shift to reach equilibrium?
Identify the correct comparison rule: if $Q<K$, which direction does the reaction shift to reach equilibrium?
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Shifts right (toward products). System needs more products to reach equilibrium.
Shifts right (toward products). System needs more products to reach equilibrium.
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Identify the correct comparison rule: if $Q>K$, which direction does the reaction shift to reach equilibrium?
Identify the correct comparison rule: if $Q>K$, which direction does the reaction shift to reach equilibrium?
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Shifts left (toward reactants). System has too many products relative to equilibrium.
Shifts left (toward reactants). System has too many products relative to equilibrium.
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Identify the correct comparison rule: if $Q=K$, what is the system’s status?
Identify the correct comparison rule: if $Q=K$, what is the system’s status?
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At equilibrium (no net shift). Forward and reverse rates are equal.
At equilibrium (no net shift). Forward and reverse rates are equal.
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State the formula relating $K_p$ and $K_c$ using $\Delta n_{gas}$ and $R$ and $T$.
State the formula relating $K_p$ and $K_c$ using $\Delta n_{gas}$ and $R$ and $T$.
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$K_p=K_c(RT)^{\Delta n_{gas}}$. Converts between pressure and concentration units.
$K_p=K_c(RT)^{\Delta n_{gas}}$. Converts between pressure and concentration units.
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State the formula for $Q_p$ for $aA(g)+bB(g) \rightleftharpoons cC(g)+dD(g)$ using partial pressures.
State the formula for $Q_p$ for $aA(g)+bB(g) \rightleftharpoons cC(g)+dD(g)$ using partial pressures.
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$Q_p = \frac{(P_C)^c(P_D)^d}{(P_A)^a(P_B)^b}$. Uses partial pressures instead of concentrations for gas-phase species.
$Q_p = \frac{(P_C)^c(P_D)^d}{(P_A)^a(P_B)^b}$. Uses partial pressures instead of concentrations for gas-phase species.
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What is the relationship between $K$ and $Q$ at equilibrium for a reaction mixture?
What is the relationship between $K$ and $Q$ at equilibrium for a reaction mixture?
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At equilibrium, $Q = K$. System reaches equilibrium when reaction quotient equals equilibrium constant.
At equilibrium, $Q = K$. System reaches equilibrium when reaction quotient equals equilibrium constant.
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State the formula for $Q_c$ for $aA + bB \rightleftharpoons cC + dD$ using molar concentrations.
State the formula for $Q_c$ for $aA + bB \rightleftharpoons cC + dD$ using molar concentrations.
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$Q_c = \frac{[C]^c[D]^d}{[A]^a[B]^b}$. Products over reactants, each raised to its stoichiometric coefficient.
$Q_c = \frac{[C]^c[D]^d}{[A]^a[B]^b}$. Products over reactants, each raised to its stoichiometric coefficient.
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Which species are omitted from $Q$ and $K$ expressions: pure solids and pure liquids or aqueous solutes?
Which species are omitted from $Q$ and $K$ expressions: pure solids and pure liquids or aqueous solutes?
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Pure solids and pure liquids are omitted. Their activities equal 1, so they don't affect the equilibrium expression.
Pure solids and pure liquids are omitted. Their activities equal 1, so they don't affect the equilibrium expression.
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What is the exponent on each term in a $Q$ or $K$ expression relative to the balanced chemical equation?
What is the exponent on each term in a $Q$ or $K$ expression relative to the balanced chemical equation?
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Each exponent equals its stoichiometric coefficient. Reflects how many moles of each species participate in the reaction.
Each exponent equals its stoichiometric coefficient. Reflects how many moles of each species participate in the reaction.
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Identify the correct reaction direction if $Q < K$ for the current mixture.
Identify the correct reaction direction if $Q < K$ for the current mixture.
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The reaction proceeds forward (toward products). More products must form to increase $Q$ until it equals $K$.
The reaction proceeds forward (toward products). More products must form to increase $Q$ until it equals $K$.
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Identify the correct reaction direction if $Q > K$ for the current mixture.
Identify the correct reaction direction if $Q > K$ for the current mixture.
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The reaction proceeds in reverse (toward reactants). More reactants must form to decrease $Q$ until it equals $K$.
The reaction proceeds in reverse (toward reactants). More reactants must form to decrease $Q$ until it equals $K$.
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What is the correct conclusion if $Q = K$ for a reaction mixture at a fixed temperature?
What is the correct conclusion if $Q = K$ for a reaction mixture at a fixed temperature?
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The system is at equilibrium. No net change occurs; forward and reverse rates are equal.
The system is at equilibrium. No net change occurs; forward and reverse rates are equal.
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State the expression for $K$ of the reverse reaction in terms of $K$ for the forward reaction.
State the expression for $K$ of the reverse reaction in terms of $K$ for the forward reaction.
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$K_{\text{reverse}} = \frac{1}{K_{\text{forward}}}$. Products and reactants swap positions, inverting the ratio.
$K_{\text{reverse}} = \frac{1}{K_{\text{forward}}}$. Products and reactants swap positions, inverting the ratio.
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State the expression for $K$ when the entire balanced equation is multiplied by a factor $n$.
State the expression for $K$ when the entire balanced equation is multiplied by a factor $n$.
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$K_{\text{new}} = K^n$. Each concentration term gets raised to the power $n$.
$K_{\text{new}} = K^n$. Each concentration term gets raised to the power $n$.
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