NEET Practice Questions (MCQs) with Answers & Solutions

(d) Common ion effect is noticed only for weak electrolyte dissociation H₂SO₄ is strong electrolyte.

(c) Since, OH^- are generated from weak acid (H₂O), a weak acid (like CO₂) should be used to remove it because of strong acid (HCl) reverse the reaction. KOH increases the concentration of OH^-, thus again shifts the reaction in backward side. CO₂  combines with OH^- to give carbonate which is easily removed. SO₂ reacts with water to give strong acid, so it cannot be used.

(d) According to law of mass action, the rate of a reaction is directly proportional to the product of active masses or molar concentrations of reactions.

                     A+B$\to$product

Rate of reaction $\propto$[A][B]

(a) More is the acidic character, lesser is basic character of conjugate base.

(b) Boiling temperature increases with increase in pressure.

(a) HCl is acid. Its pH will be <7.

(c) In 0.1 M NaCl, the solubility of AgCl is minimum due to the phenomenon of common ion effect.

(c) The highest pH refers to the basic solution containing OH^- ions. Therefore, the basic salt releasing more OH^- ions on hydrolysis will give highest pH in water.

Only the salt of strong base and weak acid would release more OH- ions on hydrolysis. Among the given salts, Na₂CO₃ corresponding to the basic salt as it is formed by the neutralisation of NaOH [strong base] and H₂CO₃ [weak acid].

            C${\mathrm{O}}_3^{2-}$ + H₂O $\rightleftharpoons$ HC${\mathrm{O}}_3^{-}$ + OH^-

(b) NH₄Cl is acidic due to hydrolysis of ${\mathrm{NH}}_4^{+}$;

                     ${\mathrm{NH}}_4^{+}$ + H₂O $\rightleftharpoons$NH₄OH +H⁺ ; pH <7.

(c)  X₂(g) + 4Y₂(g) $\rightleftharpoons$2XY₄ (g); where

          $∆$H<0 and $∆$n<0  [$∆$n= n_P - n_R]

.^.. The forward reaction is favored at high pressure and low temperature. (According to Le-Chateliers principle)