Question

True or False

t. For an exothermic reaction, the equilibrium constant, Kc, becomes smaller as the temperature increases and larger as the temperature decreases. u. The gas-phase equilibrium shown below is used to produce ammonia, NH3, for commercial applications. The NH3 yield can be increased by decreasing the temperature, increasing the pressure, and removing some NH; from the mixture. N2(g) + 3H2(g) - 2NH3() AH = -94 kJ. v. For the gas-phase equilibrium described above (see problemlu), an increase in pressure will force the reaction to the right. This results in fewer moles of gas and a lower overall pressure. w. The equilibrium constant, Ke, can be used to predict the direction and completeness of the equilibrium reactions shown below. (1) Aaq) B(aq) K = 500 A(aq) B(aq) K, -0.005 Old X. With a larger Ke value, reaction (1) is expected to produce a lower concentration of product B than reaction (2). (Assume that the experimental conditions for both reactions are identical.) (1) A(aq) B(aq) K-500 (2) A(aq) B(aq) K = 0.005 too mpe banda y. If the direction of an equilibrium reaction is reversed, the new Kc is simply the reciprocal of the old Kc (i.e., new Kc = 1/old Kc). 2. Kc for the reaction, 2NO(g) + O2(9)2NO2(g) is SE13 at 298K. If the reaction is multiplied by 2 to give the new equation, 4NO(g) + 202(0)4NO2(g), Kc should remain the same. dilip aa. The larger the equilibrium constant for a reaction, the faster should be the reaction.

Answer 1

Sol :-

(t). For exothermic reaction, the equilibrium cionstant K_c , becomes smaller as the temperature increases and larger as the temperature decreases is TRUE. Because according to Le-Chatelier's principle, if the temperature of exothermic reaction (in which heat evolved) increases than K_c decreases as equilibrium shift in reactants side.

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(u). Yield of NH₃ (g) increases by :

1). Decreases the temperature because given reaction is exothermic (as ΔH = -ve) so, according to Le-Chatelier's principle, if the temperature of exothermic reaction (in which heat evolved) increases than K_c decreases as equilibrium shift in reactants side.

2). Increases the pressure because according to Le-Chatelier's principle, if pressure of the equilibrium mixture increases then equilibrium will shift in that direction where number of moles of gases are less that towards products side.

3). Removing some NH₃ because according to Le-Chatelier's principle, if concentration of products decreases then equilibrium wilkl shift in products side.

Hence, given statement is TRUE.

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(v). Given statement is TRUE because according to Le-Chatelier's principle, if pressure of the equilibrium mixture increases then equilibrium will shift in that direction where number of moles of gases are less that towards products side.

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(w). Given statement is TRUE. Because if the value of K_c < 1 it means reactants are favored over products and if the value of K_c > 1 it means products are favored over reactants.

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(x). Given statement is FALSE. Because larger value of K_c in reaction (1) produce more concentration of B.

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(y). Given statement is TRUE. Because for reverse reaction new K_c will be reciprocal of old.

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(z). Given statement is FALSE. Because new K_c will changes

and

New K_c = (old K_c)²

= (5.0 x 10¹³)²

= 2.5 x 10²⁷