Equilibrium PYQs

In a qualitative analysis, Bi³⁺ is detected by appearance of precipitate of BiO(OH)(s). Calculate pH when the following equilibrium is established at 298 K: BiO(OH)(s) ⇌ BiO⁺(aq) + OH⁻(aq), K = 4 × 10⁻¹⁰ (Given: log2 = 0.3010)

At 298 K, a certain buffer solution contains equal concentrations of X⁻ and HX. K$_b$ for X⁻ is 10⁻¹⁰. What is the pH of this buffer solution?

Phenolphthalein is used as an indicator for the titration of sodium hydroxide solution against a standard solution of oxalic acid. The colour change observed at alkaline pH close to the equivalence point is:

Given below are certain reactions. Identify the reaction for which Kp ≠ Kc.

Phosphoric acid ionizes in three steps with their ionization constant values $K_{a1}$, $K_{a2}$ and $K_{a3}$, respectively, while $K$ is the overall ionization constant. Which of the following statements are true? A. $\log K = \log K_{a1} + \log K_{a2} + \log K_{a3}$ B. $H_3PO_4$ is a stronger acid than $H_2PO_4^{-}$ and $HPO_4^{2-}$. C. $K_{a1} > K_{a2} > K_{a3}$ D. $K_{a1} = \dfrac{K_{a3} + K_{a2}}{2}$ Choose the correct answer from the options given below:

Higher yield of NO in $N_2(g) + O_2(g) \rightleftharpoons 2NO(g)$ can be obtained at [ΔH of the reaction = +180.7 kJ mol⁻¹] A. higher temperature B. lower temperature C. higher concentration of $N_2$ D. higher concentration of $O_2$ Choose the correct answer from the options given below:

For the reaction: $2A \rightleftharpoons B + C$ $K_c = 4\times10^{-3}$ At a given time, the composition of reaction mixture is: $[A]=[B]=[C]=2\times10^{-3}\,M$ Then, which of the following is correct?

In which of the following equilibria, Kₚ and K$_c$ are NOT equal?

Consider the following reaction in a sealed vessel at equilibrium with concentrations of: $N_2=3.0\times10^{-3}\,M,\quad O_2=4.2\times10^{-3}\,M$ and $NO=2.8\times10^{-3}\,M$ $2NO_{(g)} \rightleftharpoons N_2{}_{(g)}+O_2{}_{(g)}$ If $0.1\,\text{mol L}^{-1}$ of $NO_{(g)}$ is taken in a closed vessel, what will be the degree of dissociation $(\alpha)$ of $NO_{(g)}$ at equilibrium?

The equilibrium concentrations of the species in the reaction A + B ⇌ C + D are 2, 3, 10 and 6 mol L⁻¹, respectively at 300 K. ΔG° for the reaction is (R = 2 cal/mol K)

3O₂(g) ⇌ 2O₃(g) For the above reaction at 298 K, Kc is found to be 3.0 × 10⁻⁵⁹. If the concentration of O₂ at equilibrium is 0.040 M, then concentration of O₃ at equilibrium is:

Statement I: Acid strength increases in the order given as HF << HCl << HBr << HI. Statement II: As the size of elements F, Cl, Br, I increases down the group, the bond strength of HF, HCl, HBr and HI decreases and so acid strength increases. In the light of the above statements, choose the correct answer from the options given below.

The $pK_b$ of dimethylamine and $pK_a$ of acetic acid are 3.27 and 4.77 respectively at T (K). The correct option for the pH of dimethylammonium acetate solution is:

In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it?

Find out the solubility of Ni(OH)₂ in 0.1 M NaOH. Given that the ionic product of Ni(OH)₂ is 2 × 10⁻¹⁵.

Hydrolysis of sucrose is given by the following reaction: Sucrose + H₂O ⇌ Glucose + Fructose If the equilibrium constant (K$_c$) is 2 × 10¹³ at 300 K, the value of Δ$_r$G$^⊖$ at the same temperature will be:

The pH of $0.01\ M$ NaOH (aq) solution will be

Which of the following cannot act both as Bronsted acid and as Bronsted base?

Which one of the following conditions will favour maximum formation of the product in the reaction,

The solubility of BaSO₄ in water is 2.42 × 10⁻³ g L⁻¹ at 298 K. The value of its solubility product (Ksp) will be (Given molar mass of BaSO₄ = 233 g mol⁻¹)

The equilibrium constants of the following reactions are:

Concentration of the $Ag^+$ ions in a saturated solution of $Ag_2C_2O_4$ is $2.2 \times 10^{-4}\,\text{mol L}^{-1}$. The solubility product of $Ag_2C_2O_4$ is:

A 20 litre container at 400 K contains CO₂(g) at pressure 0.4 atm and an excess of SrO (neglect volume of solid SrO). The volume of the container is now decreased by moving the movable piston fitted in the container. The maximum volume of the container, when pressure of CO₂ attains its maximum value, will be: (Given that : SrCO₃(s) ⇌ SrO(s) + CO₂(g), K$_p$ = 1.6 atm)

The percentage of pyridine $(C_5H_5N)$ that forms pyridinium ion $(C_5H_5N^+H)$ in a $0.10\ \text{M}$ aqueous pyridine solution $(K_b\text{ for }C_5H_5N = 1.7 \times 10^{-9})$ is:

The solubility of $AgCl(s)$ with solubility product $1.6 \times 10^{-10}$ in $0.1\ \text{M}\ NaCl$ solution would be:

If the equilibrium constant for $$\mathrm{N_2(g) + O_2(g) \rightleftharpoons 2NO(g)}$$ is K, the equilibrium constant for $$\mathrm{\frac{1}{2}N_2(g) + \frac{1}{2}O_2(g) \rightleftharpoons NO(g)}$$ will be:

Which one of the following pairs of solution is not an acidic buffer?

What is the pH of the resulting solution when equal volumes of 0.1 M NaOH and 0.01 M HCl are mixed?

Which of the following salts will give highest pH in water?

Using the Gibbs energy change, ΔG° = +63.3 kJ, for the following reaction, $$Ag₂CO₃ ⇌ 2Ag + (aq) + CO₃²⁻(aq)$$ the Kₛₚ of Ag₂CO₃(s) in water at 25°C is: (R = 8.314 J K⁻¹ mol⁻¹)

Given that the equilibrium constant for the reaction $$2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$$ has a value of 278 at a particular temperature. What is the value of the equilibrium constant for the following reaction at the same temperature? $$SO_3(g) \rightleftharpoons SO_2(g) + \frac{1}{2}O_2(g)$$

Given the reaction between two gases represented by A₂ and B₂ to give the compound AB: $$A_2(g) + B_2(g) \rightleftharpoons 2AB(g)$$ At equilibrium, the concentration: $$[A_2] = 3.0 \times 10^{-3} M$$ $$[B_2] = 4.2 \times 10^{-3} M$$ $$[AB] = 2.8 \times 10^{-3} M$$ If the reaction takes place in a sealed vessel at 527°C, then the value of (KC) will be:

In qualitative analysis, the metals of Group I can be separated from other ions by precipitating them as chloride salts. A solution initially contains $Ag^+$ and $Pb^{2+}$ at a concentration of $0.10\,M$. Aqueous HCl is added to this solution until the $Cl^-$ concentration is $0.10\,M$. What will be the concentrations of $Ag^+$ and $Pb^{2+}$ at equilibrium? Given: $$K_{sp}(AgCl)=1.8\times10^{-10}$$ $$K_{sp}(PbCl_2)=1.7\times10^{-5}$$

The reaction: 2A(g) + B(g) ⇌ 3C(g) + D(g) is begun with the concentrations of A and B both at an initial value of 1.00 M. When equilibrium is reached, the concentration of D is measured and found to be 0.25 M. The value of equilibrium constant for this reaction is given by the expression:

The ionization constant of ammonium hydroxide is $1.77 \times 10^{-5}$ at $298\,K$. Hydrolysis constant of ammonium chloride is:

The dissociation constants of acetic acid and HCN at $25^\circ C$ are $1.5 \times 10^{-5}$ and $4.5 \times 10^{-10}$ respectively. The equilibrium constant for: $$\mathrm{CN^- + CH_3COOH \rightleftharpoons HCN + CH_3COO^-}$$ would be:

The value of equilibrium constant for the reaction $$HI(g) ⇌ 1/2 H₂(g) + 1/2 I₂ (g)$$ is 8.0. The equilibrium constant of the reaction $$H₂(g) + I₂ (g) ⇌ 2HI(g)$$ will be

Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the H⁺ ion concentration in the mixture?

The values of Kₚ₁ and Kₚ₂ for the reactions $$X ⇌ Y + Z .........(1)$$ $$A ⇌ 2B .............(2)$$ are in the ratio 9 : 1. If the degree of dissociation of X and A are equal, then the total pressures at equilibrium for reactions (1) and (2) are in the ratio

If the concentration of OH⁻ ions in the reaction $$Fe(OH)₃(s) ⇌ Fe³⁺(aq) + 3OH⁻(aq)$$ is decreased by 1/4 times, then equilibrium concentration of Fe³⁺ will increase by

The dissociation equilibrium of a gas AB₂ can be represented as: 2AB₂(g) ⇌ 2AB(g) + B₂(g) The degree of dissociation is x and is small compared to 1. The expression relating the degree of dissociation (x) with equilibrium constant Kp and total pressure P is

Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest pH?

N₂O₄ dissociates according to N₂O₄(g) ⇌ 2NO₂(g) with degree of dissociation α = 0.4. Establish the relation between Kχ and Kp and calculate Kp if the total pressure is 1 atm.

For the reaction CH₄(g) + 2O₂(g) ⇌ CO₂(g) + 2H₂O(l), ΔrH = -170.8 kJ mol⁻¹. Which of the following statements is not true?

At $25^\circ C$, the dissociation constant of a base, $BOH$, is $1.0 \times 10^{-12}$. The concentration of hydroxyl ions in $0.01\,M$ aqueous solution of the base would be:

Equilibrium constants $K_1$ and $K_2$ for the following equilibria: $$NO(g) + \frac{1}{2}O_2(g) \rightleftharpoons NO_2(g) \quad (K_1)$$ and $$2NO_2(g) \rightleftharpoons 2NO(g) + O_2(g) \quad (K_2)$$ are related as: