Equilibrium

What effect does a catalyst have on the equilibrium position of a reaction?
(a) A catalyst favours the formation of products
(b) A catalyst favours the formation of reactants
(c) A catalyst does not change the equilibrium position of a reaction
(d) A catalyst may favour reactants or product formation, depending upon the direction in which the reaction is written.

On addition of acetate ions to an acetic acid solution, the concentration of hydrogen ions, [H⁺]

(a) Becomes zero                     (b) Is unchanged                        (c) Increases                             (d) Decreases

As the size of A increases down the group, H-A bond strength decreases and so the acid strength 

(a) Increases                                 (b) Decreases

(c) Remains constant                     (d) Becomes negligible

A sparingly soluble salt having general formula A^p+_x B^q- _y and molar solubility S is in equilibrium with its saturated solution. Derive a relationship between the solubility and solubility product for such salt.

A sparingly soluble salt having general formula A^p+_x B^q- _y and molar solubility S is in equilibrium with its saturated solution. Derive a relationship between the solubility and solubility product for such salt.

Assertion (A): In the dissociation of PCl₅ at constant pressure and temperature addition of helium at equilibrium increases the dissociation of PCl₅ .

Reason (R) : Helium removes Cl₂ from the field of action.

(i) Both A and R are true and R is correct explanation of A.

(ii) Both A and R are true but R is not correct explanation of A.

(iii) A is true but R is false.

(iv) Both A and R are false.

Assertion (A): An aqueous solution of ammonium acetate can act as a buffer.

 Reason (R) : Acetic acid is a weak acid and NH₄OH is a weak base.

(i) Both A and R are true and R is correct explanation of A.

(ii) Both A and R are true but R is not correct explanation of A.

(iii) A is false but R is true.

(iv) Both A and R are false.

Assertion (A) : Aqueous solution of ammonium carbonate is basic.

Reason (R) : Acidic/basic nature of a salt solution of a salt of weak acid and weak base depends on K_a and K_b value of the acid and the base forming it.

(i) Both A and R are true and R is correct explanation of A.

(ii) Both A and R are true but R is not correct explanation of A.

(iii) A is true but R is false.

(iv) Both A and R are false.

Assertion (A): For any chemical reaction at a particular temperature, the equilibrium constant is fixed and is a characteristic property.

Reason (R) : Equilibrium constant is independent of temperature.

(i) Both A and R are true and R is correct explanation of A.

(ii) Both A and R are true but R is not correct explanation of A.

(iii) A is true but R is false.

(iv) Both A and R are false

Assertion (A): The ionisation of hydrogen sulphide in water is low in the presence of hydrochloric acid.

 Reason (R) : Hydrogen sulphide is a weak acid.

(i) Both A and R are true and R is correct explanation of A.

(ii) Both A and R are true but R is not correct explanation of A.

(iii) A is true but R is false

(iv) Both A and R are false