Q: For the following equilibrium, $ N_{2} O_{4} \rightleftharpoons $ $ 2 N O_{2} $ in gaseous phase, $ N O_{2} $ is $ 50 \% $ of the total volume when equilibrium is set up. Hence, percent of dissociation of $ N_{2} O_{4} $ is:

$ 66.66 \% $. If 1 mole of N2O4 dissociates by x, the equilibrium amounts become N2O4 = 1−x and NO2 = 2x, so total moles = 1+x. Since NO2 is 50% of the mixture, 2x/(1+x)=1/2. Solving gives x=2/3, so the dissociation is 66.66%.

Q: One mole of ethanol is treated with one mole of ethanoic acid at $ 25 . $ One-forth of the acid changes into ester at equilibrium. The equilibrium constant for the reaction will be:

$ 4 / 9 $. If one-fourth of the acid reacts, then 0.25 mol each of ethanol and ethanoic acid are consumed, forming 0.25 mol ester and 0.25 mol water. Substituting these equilibrium amounts into the equilibrium expression gives K = (0.25×0.25)/(0.75×0.75) = 4/9.

Q: The following reaction occurs in the Blast Furnace where ion ore is reduced to iron metal: $ \boldsymbol{F e}_{2} \boldsymbol{O}_{3}(\boldsymbol{s})+\boldsymbol{3} \boldsymbol{C O}(\boldsymbol{g}) \rightleftharpoons \boldsymbol{2} \boldsymbol{F} \boldsymbol{e}(l)+ $ $ 3 C O(g) $ Using

Removal of $ C O_{2} $. In a heterogeneous equilibrium, pure solids and liquids are omitted from the equilibrium expression, so changing their amount does not shift the equilibrium. Removing CO2 does not disturb this reaction because CO2 is not a reactant or product in the given equilibrium as written.

Question 1

Which of the following will change the value of the equilibrium constant for the reaction? $ N_{2}(g)+O_{2}(g) \leftrightharpoons 2 N O(g) $

Accepted Answer

Increase the temperature. The equilibrium constant is only affected by temperature changes because it is related to the reaction's enthalpy and Gibbs free energy.

Question 2

The state of equilibrium refers to:

Accepted Answer

Dynamic state. Equilibrium is called a dynamic state because microscopic processes still occur, but they balance each other so there is no net change. The system appears unchanged overall, even though activity continues internally.

Question 3

For the following equilibrium, $ N_{2} O_{4} \rightleftharpoons $ $ 2 N O_{2} $ in gaseous phase, $ N O_{2} $ is $ 50 \% $ of the total volume when equilibrium is set up. Hence, percent of dissociation of $ N_{2} O_{4} $ is:

Accepted Answer

$ 66.66 \% $. If 1 mole of N2O4 dissociates by x, the equilibrium amounts become N2O4 = 1−x and NO2 = 2x, so total moles = 1+x. Since NO2 is 50% of the mixture, 2x/(1+x)=1/2. Solving gives x=2/3, so the dissociation is 66.66%.

Question 4

One mole of ethanol is treated with one mole of ethanoic acid at $ 25 . $ One-forth of the acid changes into ester at equilibrium. The equilibrium constant for the reaction will be:

Accepted Answer

$ 4 / 9 $. If one-fourth of the acid reacts, then 0.25 mol each of ethanol and ethanoic acid are consumed, forming 0.25 mol ester and 0.25 mol water. Substituting these equilibrium amounts into the equilibrium expression gives K = (0.25×0.25)/(0.75×0.75) = 4/9.

Question 5

The following reaction occurs in the Blast Furnace where ion ore is reduced to iron metal: $ \boldsymbol{F e}_{2} \boldsymbol{O}_{3}(\boldsymbol{s})+\boldsymbol{3} \boldsymbol{C O}(\boldsymbol{g}) \rightleftharpoons \boldsymbol{2} \boldsymbol{F} \boldsymbol{e}(l)+ $ $ 3 C O(g) $ Using

Accepted Answer

Removal of $ C O_{2} $. In a heterogeneous equilibrium, pure solids and liquids are omitted from the equilibrium expression, so changing their amount does not shift the equilibrium. Removing CO2 does not disturb this reaction because CO2 is not a reactant or product in the given equilibrium as written.

Question 6

Haber's process is a/an:

Accepted Answer

exothermic process. Haber's process synthesizes ammonia from nitrogen and hydrogen, and this reaction releases heat. A negative enthalpy change means the process is exothermic.

Question 7

2 moles of $ P C l_{5} $ when heated in a closed vessels of 2 litre capacity at equilibrium $ 40 \% $ of $ P C l_{5} $ dissociated in $ P C l_{3} $ and $ C l_{2} . $ What is the value of the equilibrium constant?

Accepted Answer

0.267. If 40% of 2 moles dissociate, 0.8 mol of PCl5 reacts to form 0.8 mol each of PCl3 and Cl2, leaving 1.2 mol PCl5. In a 2 L vessel, the equilibrium concentrations give Kc = ([PCl3][Cl2])/[PCl5] = 0.267.

Question 8

The equilibrium constant for a reaction is $ K, $ and the reaction quotient is $ Q $. For a reaction mixture, the ratio $ \frac{K}{Q} $ is 0.33 This means that:

Accepted Answer

the reaction mixture will equilibrium to form more product species. Since K/Q = 0.33, Q is greater than K. That means the mixture has too much reactant relative to product compared with equilibrium, so the reaction shifts forward to make more products until Q = K.

Question 9

The reaction quotient ( $ Q $ ) predicts

Accepted Answer

the direction of equilibrium to be attained. The reaction quotient uses the current concentrations or activities, so it can indicate whether the reaction will move forward or backward to reach equilibrium. At equilibrium, Q equals K, but Q itself is not the equilibrium ratio.

NEET Chemistry: Chemical Equilibrium questions with solutions

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