Equilibrium

Ammonium ion is

• neither an acid nor base

• both an acid and a base

• a conjugate acid

• a conjugate base

Heat of neutralisation of weak acid and strong base is less than the heat of neutralisation of strong acid and strong base due to

• energy has to be spent for the total dissociation of weak acid

• salt of weak acid and strong base is not stable

• incomplete dissociation of weak acid

• incomplete neutralisation of weak acid

Solubility product of a salt AB is 1 × 10^-8 in a solution in which concentration of A is 10^-3 M. The salt will precipitate when the concentration of B becomes more than

• 10^-4 M

• 10^-7 M

• 10^-6 M

• 10^-5 M

In a lime kiln to get higher yield of CO₂, the measure that can be taken is

• to remove

• to add more CaCO₃

• to mamtain high temperature

• to pump out CO₂

In the reversible reaction,

A(s) + B(g) $\rightleftharpoons$C (g) + D(g) ΔG^° = -350kJ

Which one of the following statements is true?

• The entropy change is negative

• Equilibrium constant is greater than one

• The reaction should be instantaneous

• The reaction is thermodynamically not feasible

pH value of which one of the following is not equal to one?

• 0.1 M CH₃COOH

• 0.1 M HNO₃

• 0.05 M H₂SO₄

• 50 cm³ 0.4 M HCl + 50 cm³ 0.2 M NaOH

The reaction quotient 'Q' is useful in predicting the direction of the reaction. Which of the following is incorrect?

• If Q_c < K_c, the forward reaction is favoured

• If Q_c > K_c, the forward reaction is favoured

• If Q_c >K_c, the forward reaction is favoured and Q_c =K_c, no reaction occur.

• None of these

pH scale was introduced by :

• Arrhenius

• Sorensen

• Lewis

• Lowry

The solubility of CaF₂ in pure water is 2.3 × 10^-4 mol dm³. Its solubility product will be:

• 4.6 × 10^-4

• 4.6 × 10^-8

• 6.9 × 10^-12

• 4.9 × 10^-11

Microcosmic salt is

• Na₄P₂O₇

• Na(NH₄)HPO₄

• Na(NH₃)HPO₄ 4H₂O

• MgNH₄PO₄