Equilibrium CBSE Questions & Answers

Which of the following is not a general characteristic of equilibria involving physical processes?

\({\text{PC}}{{\text{l}}_{\text{5}}}\), \({\text{PC}}{{\text{l}}_{\text{3}}}\) and \({\text{C}}{{\text{l}}_{\text{2}}}\) are at equilibrium at 500K in a closed container and their concentrations are \(0.{\text{8 }} \times {\text{ 1}}{0^{ - {\text{3}}}}{\text{mol }}{{\text{L}}^{ - {\text{1}}}},{\text{ 1}}.{\text{2 }} \times {\text{ 1}}{0^{ - {\text{3}}}}{\text{mol }}{{\text{L}}^{ - {\text{1}}}}{\text{and 1}}.{\text{2 }} \times {\text{ 1}}{0^{ - {\text{3}}}}{\text{mol }}{{\text{L}}^{ - {\text{1}}}}\) respectively. The value of \({{\text{K}}_{\text{c}}}\) for the reaction \({\text{PC}}{{\text{l}}_{\text{5}}}\) (g) \( \rightleftharpoons \) \({\text{PC}}{{\text{l}}_{\text{3}}}\) (g) + \({\text{C}}{{\text{l}}_{\text{2}}}\) (g) will be

Which of the following statements is incorrect?

When hydrochloric acid is added to cobalt nitrate solution at room temperature, the following reaction takes place and the reaction mixture becomes blue. On cooling the mixture it becomes pink. On the basis of this information mark the correct answer. \({\left[ {{\text{Co }}\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right){\text{6}}} \right]^{{\text{3}} + }}\left( {{\text{aq}}} \right){\text{ }} + {\text{ 4C}}{{\text{l}}^ - }\left( {{\text{aq}}} \right)\) \( \rightleftharpoons \) \({\left[ {{\text{CoC}}{{\text{l}}_{\text{4}}}} \right]^{{\text{2}} - }}\left( {{\text{aq}}} \right){\text{ }} + {\text{ 6}}{{\text{H}}_{\text{2}}}{\text{O}}\) (l )

The pH of neutral water at \({\text{25}}^\circ {\text{C}}\) is 7.0. As the temperature increases, ionisation of water increases, however, the concentration of \({{\text{H}}^ + }\) ions and \(O{H^ - }\) ions are equal. What will be the pH of pure water at \({\text{6}}0^\circ {\text{C}}?\)

The ionization constant of an acid, \({{\text{K}}_{\text{a}}}\), is the measure of strength of an acid. The Ka values of acetic acid, hypochlorous acid and formic acid are \({\text{1}}.{\text{74 }} \times {\text{ 1}}{0^{ - {\text{5}}}},{\text{ 3}}.0{\text{ }} \times {\text{ 1}}{0^{ - {\text{8}}}}{\text{and 1}}.{\text{8 }} \times {\text{ 1}}{0^{ - {\text{4}}}}\) respectively. Which of the following orders of pH of 0.1 mol dm-3 solutions of these acids is correct?

\({{\text{K}}_{{\text{a1}}}},{{\text{K}}_{{\text{a2}}}}\) and \({{\text{K}}_{{\text{a3}}}}\) are the respective ionisation constants for the following reactions.\({{\text{H}}_{\text{2}}}{\text{S}}\) \( \rightleftharpoons \) \({\text{H}} + {\text{ }} + {\text{ HS}}--\) \({\text{HS}}-\) \( \rightleftharpoons \) \({\text{H}} + {\text{ }} + {\text{ S2}}-\)\({{\text{H}}_{\text{2}}}{\text{S}}\) \( \rightleftharpoons \) \({\text{2H}} + {\text{ }} + {\text{ S2}}-\)The correct relationship between \({{\text{K}}_{{\text{a1}}}},{{\text{K}}_{{\text{a2}}}}\) and \({{\text{K}}_{{\text{a3}}}}\) is

Acidity of \({\text{B}}{{\text{F}}_{\text{3}}}\)can be explained on the basis of which of the following concepts?

Which of the following will produce a buffer solution when mixed in equal volumes?

In which of the following solvents is silver chloride most soluble?

What will be the value of pH of \(0.0{\text{1 mol d}}{{\text{m}}^{ - {\text{3}}}}{\text{CH3COOH }}\left( {{{\text{K}}_{\text{a}}} = {\text{ 1}}.{\text{74 }} \times {\text{ 1}}{0^{ - {\text{5}}}}} \right)?\)

\({{\text{K}}_{\text{a}}}{\text{for C}}{{\text{H}}_{\text{3}}}{\text{COOH is 1}}.{\text{8 }} \times {\text{ 1}}{0^{ - {\text{5}}}}{\text{andKb for N}}{{\text{H}}_{\text{4}}}{\text{OH is 1}}.{\text{8 }} \times {\text{ 1}}{0^{ - {\text{5}}}}\). The pH of ammonium acetate will be

Which of the following options will be correct for the stage of half completion of the reaction A \( \rightleftharpoons \) B.

On increasing the pressure, in which direction will the gas phase reaction proceed to re-establish equilibrium is predicted by applying the Le Chatelier’s principle. Consider the reaction. \({{\text{N}}_{\text{2}}}\left( {\text{g}} \right){\text{ }} + {\text{ 3}}{{\text{H}}_{\text{2}}}\left( {\text{g}} \right)\) \( \rightleftharpoons \) \({\text{2N}}{{\text{H}}_{\text{3}}}\) (g) Which of the following is correct, if the total pressure at which the equilibrium is established, is increased without changing the temperature?

What will be the correct order of vapour pressure of water, acetone and ether At \({\text{3}}0^\circ {\text{C}}\). Given that among these compounds, water has maximum boiling point and ether has minimum boiling point?