Equilibrium

Which of the following is a necessary condition for achieving physical equilibrium?

Sublimation is a process where a solid changes directly into vapor. Which equilibrium constant expression would apply to $Solid \rightleftharpoons Vapor$ if we use partial pressure?

When $CO_2$ gas is dissolved in water under high pressure in a sealed bottle, the system is in:

Which state of matter has the highest vapor pressure at a given temperature?

Which of the following is a characteristic of gas-liquid equilibrium?

A saturated solution of $NaCl$ is in equilibrium with its solid. If the temperature is kept constant and more water is added, what will happen to the amount of solid $NaCl$?

In the process of $CO_{2}$ gas dissolving in water to reach equilibrium in a closed bottle, what happens to the system's entropy ($\\Delta S$)?

In the context of the diagram showing the phase interface, if the system is at equilibrium, the flux of molecules from Phase A to Phase B must be equal to the flux from Phase B to Phase A. What happens if the surface area of the interface is increased?

The vapor pressure of a liquid is $P$ at temperature $T$. If the atmospheric pressure above the liquid is reduced to $P$, the liquid will:

When solid $NH_{4}Cl$ is heated in a closed tube, it decomposes into $NH_{3}(g)$ and $HCl(g)$. If more $NH_{3}(g)$ is injected into the tube at equilibrium, what happens to the amount of solid $NH_{4}Cl$?

In a saturated solution of a salt, if more salt is added:

Which of the following is a requirement for a system to reach chemical equilibrium?

If the rate of crystallization is less than the rate of dissolution, the solution is:

In the context of dynamic equilibrium, what does 'macroscopic' mean?

In a closed system containing $N_{2}O_{4}$ and $NO_{2}$ gas at equilibrium, if the temperature is kept constant and more $NO_{2}$ is added, the value of $K_{c}$ will:

In the context of the Law of Mass Action, the term 'active mass' refers to:

The constant value of the concentration of products divided by the concentration of reactants (each raised to their stoichiometric coefficients) at a specific temperature is known as:

In an experiment, $K_p$ for the reaction $A \rightleftharpoons 2B$ is $1.0 \text{ atm}$. If the total pressure at equilibrium is $1.0 \text{ atm}$, what is the mole fraction of $B$?

For the reaction $CO(g) + Cl_2(g) \rightleftharpoons COCl_2(g)$, the value of $K_c/K_p$ is:

When $NaNO_3(s)$ is heated in a closed vessel, oxygen is liberated and $NaNO_2(s)$ is left behind. At equilibrium:

For the reaction $CO_2(g) + C(s) \rightleftharpoons 2CO(g)$, what is the unit of $K_c$?

Which factor does NOT affect the value of the equilibrium constant $K_c$?

If the reaction $2A \rightleftharpoons B$ has an equilibrium constant $K_1$ and $B \rightleftharpoons 2A$ has $K_2$, then:

What is the value of $\\Delta n$ for the reaction: $3Fe(s) + 4H_2O(g) \rightleftharpoons Fe_3O_4(s) + 4H_2(g)$?

The expression $K = [Product] / [Reactant]$ for a reaction at equilibrium is derived from which law?

The unit of $K_p$ for the reaction $2NaHCO_3(s) \rightleftharpoons Na_2CO_3(s) + CO_2(g) + H_2O(g)$ is:

What happens to the numerical value of $K_c$ if the stoichiometric coefficients of a balanced equation are doubled?

In the reaction $A(s) \rightleftharpoons 2B(g) + 3C(g)$, if the partial pressure of $C$ is tripled, by what factor must the partial pressure of $B$ be changed to maintain equilibrium?

For the equilibrium $CO(g) + H_2O(g) \rightleftharpoons CO_2(g) + H_2(g)$, the value of $K_c$ is $1.0$ at $1000 K$. If we start with $1$ mol of $CO$ and $1$ mol of $H_2O$ in a $10 L$ flask, what is the equilibrium concentration of $CO_2$?

At $T K$, $K_p$ for the reaction $A(g) + B(g) \rightleftharpoons 2C(g)$ is $1.0$. If the reaction is started with $1.0$ mole of $A, 1.0$ mole of $B$ and $1.0$ mole of $C$ in a $1.0 L$ container, the concentration of $C$ at equilibrium will be:

For the equilibrium $CH_4(g) + H_2O(g) \rightleftharpoons CO(g) + 3H_2(g)$, which of the following will decrease the yield of $H_2$?

In the Haber process for the synthesis of ammonia, what is the effect of using a catalyst?

If the reaction quotient $Q_c$ is greater than the equilibrium constant $K_c$, in which direction does the reaction proceed?

In the reaction $A(s) \rightleftharpoons B(g) + C(g)$, increasing the pressure will:

In the equilibrium $Cr_2O_7^{2-} + H_2O \rightleftharpoons 2CrO_4^{2-} + 2H^+$, what happens to the color of the solution (Dichromate is orange, Chromate is yellow) if $NaOH$ is added?

For the transition $S_{rhombic} \rightleftharpoons S_{monoclinic}$, the $ΔH$ is $+2.5$ kJ. This implies that:

An endothermic reaction with more gaseous moles on the product side will be favored by:

At a given temperature, the equilibrium constant for $CO(g) + H_2O(g) \rightleftharpoons CO_2(g) + H_2(g)$ is $1.0$. If we start with $1 \text{ mole}$ of each of the four gases in a $1 \text{ L}$ container, what will happen?

In the reaction $N_2O_4(g) \rightleftharpoons 2NO_2(g)$, if the volume is increased, the degree of dissociation $\alpha$ increases. Which of the following is the correct expression for $K_p$ in terms of total pressure $P$ and $\alpha$?

For the equilibrium $SnO_2(s) + 2H_2(g) \rightleftharpoons Sn(l) + 2H_2O(g)$, the equilibrium constant $K_p$ is $0.05$ at $1000 \text{ K}$. If the partial pressure of $H_2$ is $1 \text{ atm}$, what is the equilibrium partial pressure of $H_2O$?

The solubility of $AgI$ is lowest in:

The $pH$ of a solution is $12$. The concentration of $H^+$ ions is:

Which of the following represents the ionization of a weak acid $HA$?

Adding $NH_4Cl$ to $NH_4OH$ solution will:

An aqueous solution of a salt $XY$ is formed from a weak acid $HX$ and a weak base $YOH$. Based on the relationship shown in the diagram, if the ionization constant of the acid $K_a$ is $1.0 \times 10^{-6}$ and that of the base $K_b$ is $1.0 \times 10^{-4}$, what is the $pH$ of a $0.1\ M$ solution of this salt at $298\ K$?

The concentration of $H_3O^+$ in a solution is $10^{-4}\ M$. The $pOH$ of the solution is:

When solid $NH_4Cl$ is added to an aqueous solution of $NH_4OH$, the concentration of $OH^-$ ions:

Calculate the concentration of $OH^-$ in a $0.2\ M$ solution of $NH_3$ given $K_b = 1.8 \times 10^{-5}$.

In which of the following solutions will $AgBr$ have the lowest solubility?

A $1.0\ L$ solution contains $0.1\ mol$ of $CH_3COOH$ ($K_a = 1.8 \times 10^{-5}$) and $0.1\ mol$ of $HCl$. The degree of dissociation of $CH_3COOH$ in this solution is:

Which of the following is a Lewis acid because it has an incomplete octet?

A solution with a $pH$ of 13 is:

If $K_a$ for a weak acid is $1.0 \times 10^{-5}$, what is its $pK_a$?

What is the conjugate acid of $SO_4^{2-}$?

If $S$ is the solubility of $Al(OH)_{3}$ in $mol/L$, then its $K_{sp}$ is:

The value of $pK_{w}$ at $25^{\circ}C$ is:

Which of the following is correct for the hydrolysis of $NaCN$?

Calculate the hydroxide ion concentration in $0.1\ M$ aqueous solution of $NH_3$. ($K_b = 1.8 \times 10^{-5}$)

The dissociation of $H_2S$ is suppressed by adding $HCl$ due to:

For a buffer solution, the ratio of $[Salt]/[Acid]$ was 10. If the concentration of the acid is doubled and the salt is halved, the change in pH will be:

The $pH$ of a $0.0001\ M$ solution of $HNO_3$ is:

Which of the following is the conjugate base of $NH_4^+$?

If the $K_a$ of an acid is high, the acid strength is:

The degree of ionization of a weak acid $HA$ is given by (where $C$ is concentration and $K_a$ is ionization constant):

At $298 K$, what is the concentration of $H_3O^+$ ions in a $0.01 M$ solution of $NaOH$?

Trichloroacetic acid ($CCl_3COOH$) is a much stronger acid than acetic acid ($CH_3COOH$). This is primarily due to:

In a basic buffer solution containing $NH_4OH$ and $NH_4Cl$, if the concentration of the salt ($NH_4Cl$) is increased by a factor of $10$ while keeping the base concentration constant, how will the $pOH$ change?

The $K_a$ for $HCN$ is $4.9 \times 10^{-10}$. What is the $K_b$ for $CN^-$?

Calculate the solubility of $PbCl_2$ ($K_{sp} = 1.6 \times 10^{-5}$) in water at $25^\circ C$.

What is the pH of a solution prepared by mixing equal volumes of $0.1\ M\ NaOH$ and $0.1\ M\ CH_3COOH$? (Given $pK_a = 4.74$)

Identify the buffer system used in the qualitative analysis of Group III basic radicals.

Which of the following is NOT a property of a buffer solution?

What is the primary role of the salt in a weak acid-salt buffer?

Which of the following will have the highest buffer capacity?

Which of the following chemical equilibria represents the buffering action when a strong base is added to an ammonium buffer?

If the $pH$ of a buffer solution is 10, and it is a basic buffer with $pK_b = 5$, what is the ratio of $[Salt]/[Base]$?

A buffer solution has $[Salt] = [Acid]$. If the $K_a$ of the acid is $4 \times 10^{-6}$, what is the $pH$ of the buffer? (Given $\log 4 = 0.6$)

A basic buffer is $0.1\,M$ in $NH_3$ and $0.1\,M$ in $NH_4Cl$. If $K_b$ for $NH_3$ is $1.8 \times 10^{-5}$, what is the $[H^+]$ concentration in the solution?

If the $pK_a$ of a weak acid is $5.0$, in what $pH$ range will it be most effective as a buffer?

How does the buffer capacity change when the concentrations of both the weak acid and its conjugate base are doubled?

If the solubility product of $BaSO_4$ is $1.1 \times 10^{-10}$, a precipitate of $BaSO_4$ will form when equal volumes of $0.0002\ M\ BaCl_2$ and $0.0002\ M\ Na_2SO_4$ are mixed because:

What is the relationship between solubility ($s$) and $K_{sp}$ for $Li_3PO_4$?

The molar solubility of $CaF_2$ is $2 \times 10^{-4}\ M$. Its $K_{sp}$ is:

A salt $XY$ has $K_{sp} = 4 \times 10^{-10}$. A salt $XY_2$ has $K_{sp} = 4 \times 10^{-12}$. Which salt is more soluble in water?

What is the molar solubility of $PbCl_{2}$ in $0.02 M$ $NaCl$ solution? ($K_{sp}$ of $PbCl_{2} = 1.6 \times 10^{-5}$)

If $Q_{sp} < K_{sp}$ for a salt $AB$, the solution is said to be:

Which of the following describes the relationship between the solubility product ($K_{sp}$) and temperature?

What is the molar solubility of $Ca(OH)_{2}$ in a buffer of $pH = 12$? ($K_{sp} Ca(OH)_{2} = 5.5 \times 10^{-6}$)

The solubility of $AgBr$ is $5.4 \times 10^{-7} M$. What is the concentration of $Ag^{+}$ in a solution where the concentration of $Br^{-}$ is $0.01 M$?

Calculate the solubility of $Cu(OH)_{2}$ in $0.1 M$ $NaOH$. ($K_{sp} = 2.2 \times 10^{-20}$)

Which of the following gaseous reactions will be unaffected by a change in pressure?

If $Q_c = K_c$, the reaction is in a state of:

A catalyst affects the equilibrium by:

When $\Delta n$ is positive for a gaseous reaction, then:

In the homogeneous gaseous reaction $2NO(g) \rightleftharpoons N_2(g) + O_2(g)$, the dissociation of $NO$ is studied at a specific temperature. If the initial pressure of $NO$ is $1.0\ atm$ and it is found to be $40\%$ dissociated when equilibrium is reached, what is the value of the equilibrium constant $K_p$ for the reaction as written?