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Chemistry · EQUILIBRIUM
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Chemistry · EQUILIBRIUM
Consider the following equilibria at a given temperature: (1) \( \text{N}_2(\text{g}) + 3\text{H}_2(\text{g}) \rightleftharpoons 2\text{NH}_3(\text{g}) \) with equilibrium constant \( K_1 \) (2) \( \text{N}_2(\text{g}) + \text{O}_2(\text{g}) \rightleftharpoons 2\text{NO}(\text{g}) \) with equilibrium constant \( K_2 \) (3) \( \text{H}_2(\text{g}) + \frac{1}{2}\text{O}_2(\text{g}) \rightleftharpoons \text{H}_2\text{O}(\text{g}) \) with equilibrium constant \( K_3 \) The equilibrium constant \( K \) for the reaction \( 2\text{NH}_3(\text{g}) + \frac{5}{2}\text{O}_2(\text{g}) \rightleftharpoons 2\text{NO}(\text{g}) + 3\text{H}_2\text{O}(\text{g}) \) is given by:
Read answer →Chemistry · EQUILIBRIUM
Given below are statements regarding physical equilibria: (A) Equilibrium is possible only in a closed system at a given temperature. (B) Both opposing processes occur at the same rate and there is a dynamic but stable condition. (C) All measurable properties of the system remain constant. (D) When equilibrium is attained for a physical process, it is characterised by constant value of one of its parameters at a given temperature. (E) Liquid-vapour equilibrium can be established in both open and closed systems. Choose the correct answer from the options given below:
Read answer →Chemistry · EQUILIBRIUM
For a pure substance at atmospheric pressure, the temperature at which its solid and liquid phases coexist in dynamic equilibrium is called its:
Read answer →Chemistry · EQUILIBRIUM
Consider the following statements regarding the ionization of weak acids and bases: (A) Larger value of \( K_a \) indicates a stronger acid. (B) For a weak acid \( \text{HX} \), \( K_a = \frac{c\alpha^2}{1-\alpha} \), where \( \alpha \) is the degree of ionization. (C) As the initial concentration \( c \) of a weak acid decreases, its degree of ionization \( \alpha \) also decreases. (D) At 298 K, the ionization constant \( K_b \) of ammonia is \( 1.77 \times 10^{-5} \). Which of the above statements are correct?
Read answer →Chemistry · EQUILIBRIUM
The \( \text{pH} \) of a solution is decreased from \( 5.0 \) to \( 2.0 \). By what factor has the concentration of \( \text{H}^+ \) ions increased?
Read answer →Chemistry · EQUILIBRIUM
The ionic product of water at \( 310\text{ K} \) is \( 2.56 \times 10^{-14}\text{ mol}^2\text{L}^{-2} \). What is the \( \text{pH} \) of a neutral aqueous solution at this temperature? (Given: \( \log 1.6 = 0.204 \))
Read answer →Chemistry · EQUILIBRIUM
At \( 298\text{ K} \), pure water has a density of \( 1000\text{ g/L} \) and molar mass of \( 18.0\text{ g/mol} \). If the concentration of \( \text{H}^+ \) ions is \( 1.0 \times 10^{-7}\text{ M} \), what is the fraction of water molecules that are dissociated into ions?
Read answer →Chemistry · EQUILIBRIUM
At 298 K, the base dissociation constant of an organic base B is \( K_b = 2.5 \times 10^{-6} \). If the ionic product of water is \( K_w = 1.0 \times 10^{-14} \), the acid dissociation constant \( K_a \) and \( pK_a \) of its conjugate acid \( \text{BH}^+ \) are respectively:
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The pH of pure water at 298 K is equal to 7. Reason (R): As the temperature of pure water increases, its pH increases above 7. In the light of the above statements, choose the correct answer from the options given below:
Read answer →Chemistry · EQUILIBRIUM
For the dimerization reaction \( 2\text{NO}_2(\text{g}) \rightleftharpoons \text{N}_2\text{O}_4(\text{g}) \) with \( \Delta H = -57.2\text{ kJ mol}^{-1} \), what change is observed in the brown colour of the gas mixture when the temperature is lowered from \( 298\text{ K} \) to \( 270\text{ K} \) in a sealed tube?
Read answer →Chemistry · EQUILIBRIUM
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Physical equilibria can only be attained and maintained in an open system. Reason (R): In an open system, matter and energy continuously exchange with the surroundings to establish constancy. In the light of the above statements, choose the correct answer from the options given below:
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For the equilibrium \( 2\text{NOCl}(\text{g}) \rightleftharpoons 2\text{NO}(\text{g}) + \text{Cl}_2(\text{g}) \), \( K_c = 3.75 \times 10^{-6} \) at \( 1069\text{ K} \). Using \( R = 0.0831\text{ bar L mol}^{-1}\text{K}^{-1} \), what is the numerical ratio of \( K_p \) to \( K_c \)?
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At 298 K, the density of pure water is \( 1000\text{ g/L} \) and its ionic product \( K_w \) is \( 1.0 \times 10^{-14}\text{ mol}^2\text{L}^{-2} \). The ratio of dissociated water molecules to undissociated water molecules is approximately:
Read answer →Chemistry · EQUILIBRIUM
The concentration of hydrogen ion in a sample of soft drink is \( 3.8 \times 10^{-3}\text{ M} \). Given \( \log 3.8 = 0.58 \), what is the pH of the soft drink?
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Consider the following statements regarding the Bronsted-Lowry concept of acids and bases: (A) A Bronsted-Lowry acid is a proton donor. (B) The conjugate base of \( \text{HF} \) is \( \text{F}^- \). (C) A strong Bronsted acid has a strong conjugate base. (D) Water can act as both a proton donor and a proton acceptor. Which of the above statements are correct?
Read answer →Chemistry · EQUILIBRIUM
Consider the following statements regarding equilibrium constants: (A) A very large value of \( K_c \) (e.g., \( K_c > 10^3 \)) implies that products predominate over reactants at equilibrium. (B) A very small value of \( K_c \) (e.g., \( K_c < 10^{-3} \)) implies that reactants predominate strongly and the reaction proceeds rarely. (C) If \( K_c \) is between \( 10^{-3} \) and \( 10^3 \), appreciable concentrations of both reactants and products are present. (D) The value of the equilibrium constant \( K_c \) depends directly on the initial concentrations of reactants and products. Which of the above statements are correct?
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A buffer solution contains \( 0.1\text{ M} \) weak acid HA (\( \text{p}K_a = 4.74 \)) and \( 1.0\text{ M} \) of its conjugate base \( \text{A}^- \). What is the pH of this buffer solution?
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Match List-I with List-II: List-I (Fluid/Substance) List-II (Approximate pH at 298 K) A Human blood I ~1.2 B Milk of magnesia II 7.4 C Gastric juice III 10 D Black coffee IV 5.0 Choose the correct answer from the options given below:
Read answer →Chemistry · EQUILIBRIUM
At \( 500\text{ K} \), the equilibrium constant \( K_c \) for \( \text{PCl}_5(\text{g}) \rightleftharpoons \text{PCl}_3(\text{g}) + \text{Cl}_2(\text{g}) \) is \( 1.79 \). If the equilibrium concentration of \( \text{PCl}_5 \) is doubled while maintaining equilibrium at the same temperature such that \( [\text{PCl}_3] = [\text{Cl}_2] \), by what factor does the concentration of \( \text{Cl}_2 \) increase?
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Given below are two statements: Statement I: Across a period from left to right in the periodic table, the polarity of the H-A bond is the deciding factor in determining the acid strength. Statement II: Down a group in the periodic table, the electronegativity difference is the deciding factor in determining the acid strength. In the light of the above statements, choose the most appropriate answer from the options given below:
Read answer →Chemistry · EQUILIBRIUM
Which of the following equilibria represents a homogeneous equilibrium in solution phase?
Read answer →Chemistry · EQUILIBRIUM
The ionization constant of aqueous ammonia is \( K_b = 1.77 \times 10^{-5} \). If the concentration of ammonia is diluted from 0.05 M to 0.005 M at 298 K, the percentage increase in its degree of ionization (\( \alpha \)) is approximately:
Read answer →Chemistry · EQUILIBRIUM
