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Class 9Class 10First YearSecond Year
Q3. Label the sentences as True or False.i) When a reversible reaction attains equilibrium both reactants and products are present in a reaction mixture.ii) The K_{c} of the reaction$\mathrm{A}+\mathrm{B} \square \mathrm{C}+\mathrm{D}$is given by$\mathrm{K}_{\mathrm{c}}=\frac{[\mathrm{C}][\mathrm{D}]}{[\mathrm{A}][\mathrm{B}]}$therefore it is assumed that$[\mathrm{A}]=[\mathrm{B}]=[\mathrm{C}]=[\mathrm{D}]$iii) A catalyst is a substance which increases the speed of the reaction and consequently increases the yield of the product.iv) Ionic product \mathrm{K}_{\mathrm{w}} of pure water at 25^{\circ} \mathrm{C} is 10^{-14} \mathrm{~mol}^{2} \mathrm{dm}^{-6} and is represented by an expression \mathrm{K}_{\mathrm{w}} =\left[\mathrm{H}^{+}\right]\left[\mathrm{OH}^{-}\right]=10^{-14} \mathrm{~mol}^{2} \mathrm{dm}^{-6} v) \mathrm{AgCl} is a sparingly soluble ionic solid in water. Its solution produces excess of \mathrm{Ag}^{+} and \mathrm{Cl}^{-} ions.

Q14 In the equilibrium$\mathrm{PCl}_{5}(\mathrm{~g}) \square \mathrm{PCl}_{3}(\mathrm{~g})+\mathrm{Cl}_{2}(\mathrm{~g}) \Delta \mathrm{H}=+90 \mathrm{~kJ} \mathrm{~mol}^{-1}$What is the effect on(a) the position of equilibrium(b) equilibrium constant? ifi) temperature is increased

$(c) Write equilibrium constant expression for the following reactions(ii) \mathrm{Ag}^{+} (aq) +\mathrm{Fe}^{2+} (aq) \square \mathrm{Fe}^{3+} (aq) +\mathrm{Ag}(\mathrm{s})$

1. For the decomposition of dinitrogen oxide \left(\mathrm{N}_{2} \mathrm{O}\right) into nitrogen and oxygen reversible reaction takes place as follows$2 \mathrm{~N}_{2} \mathrm{O}_{(\mathrm{g})} \rightleftharpoons 2 \mathrm{~N}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}$The concentration of \mathrm{N}_{2} \mathrm{O} \mathrm{N}_{2} and \mathrm{O}_{2} are 1.1 \mathrm{~mol} \mathrm{dm}^{-3} 3.90 \mathrm{~mol} \mathrm{dm}^{-3} and 1.95 \mathrm{~mol} \mathrm{dm}^{-3} respectively at equilibrium. Find out \mathrm{K}_{\mathrm{c}} for this reaction.

$11. Write note on :(ii) dynamic equilibrium$

$13. If reaction quotient Q_{c} of a reaction is more than K_{c} what will be the direction of the reaction?$

Q15. Synthesis of ammonia by Habers process is an exothermic reaction.$\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \square 2 \mathrm{NH}_{3}(\mathrm{~g}) \ddot{A} H=-92.46 \mathrm{~kJ}$(d) What happens to equilibrium position of this reaction if \mathrm{NH}_{3} is removed from the reaction vessel from time to time?