Question

ALL WITH EXPLANATIONS please :)

12. Consider the following reaction: 2SO_2(g)  +  O_2(g)  ⇄  2SO_3(g)   +E            

Which of the following will not shift the equilibrium to the right?

            A.        Adding more O₂

            B.        Adding a catalyst

            C.        Increasing the pressure

            D.        Lowing the temperature

13.         Consider the following equilibrium system: CaCO_3(s)  ⇄ CaO_(s) +  CO_2(g)

            Which one of the following changes would cause the above system to shift left?

            A.        Add more CaO

            B.        Remove CaCO₃

            C.        Increase pressure

            D.        Remove CO2

14.         Consider the following equilibrium: SO₂Cl_2(g)  +  energy  ⇄  SO_2(g)  +  Cl_2(g)

            When the temperature is decreased, the equilibrium shifts

            A.        Left and [ SO₂Cl₂ ] increases

            B.        Left and [ SO₂Cl₂ ] decreases

            C.        Right and [ SO₂Cl₂ ] increases

            D.        Right and [ SO₂Cl₂ ] increases

15.        Consider the following equilibrium system: CO_2(g)   +  H_2(g)  ⇄  CO_(g)  +  H₂O_(g)

            Which of the following, when added to the system above, would result in a net decrease in [H₂O]?

            A. CO₂

            B. H₂

            C. CO

            D. H₂

16.         Consider the following equilibrium: C_(s)  +  2H_2(g)  ⇄ CH_4(g)  +  74 kJ

            When a small amount of solid C is added to the system

            A. [H₂] decreases

            B. [CH₄] increases

            C. The temperature increases

            D. All concentrations remain constant

17.         Consider the following equilibrium: 2NO_(g)  +  Cl_2(g)  ⇄  2NOCl_(g)

            At constant temperature and volume, Cl₂ is added to the above equilibrium   system. As equilibrium re-establishes, the

            A. [NOCl] will decrease

            B. The temperature increases

            C. [NO] will increase

            D. [NOCl] will increase

Answer 1

According to Le-Chatlier Principle, If a reaction At equilibrium is subjected to a change in Any of the reaction condition (i.e. Temperature, Pressure, Concentration or Volume) , then the reaction will shift in a direction to undo the effect of change.

12. Reaction Is:

2SO_2(g)  +  O_2(g)  ⇄  2SO_3(g)   +E

A. O₂ is added. If we add more O₂ to reaction, then the concentration of O₂ increases and to undo this effect i.e. to decrease its concentration reaction will shift in a direction in which it is consumed which is the forward direction. Hence reaction will shift right.

B. Adding a Catalyst. If we add a catalyst in a reaction at equilibrium, then it has no effect on it because Catalyst is added in a reaction to increase its rate , but it has no effect when reaction is at equilibrium.

C. Increasing the pressure. If we Increase the pressure, then reaction will shft in a direction in which it is decreased.Since the pressure is directy proportional to the number of moles of gas. Moles of gas of reactants =3 and that of products =2. So, the Pressure due to product molecules is less than that of reactant molecules. Hence reaction will shift right to decrease the pressure.

D, Lowing the temperature. If temperature is lowered, then the reaction will shift to in a direction in which temperature can be increased again. Since the reaction is exothermic in nature i.e. temperature is incresed in right direction. Hence reaction will shift right

Thus, correct option is B. Adding a catalyst.

13. Reaction is CaCO_3(s)  ⇄ CaO_(s) +  CO_2(g)

A. Add more CaO : If we add more CaO to reaction, then the concentration of CaO increases and to undo this effect i.e. to decrease its concentration reaction will shift in a direction in which it is consumed which is the backward direction. Hence reaction will shift left.

B. Remove CaCO₃ : If we remove It, then its concentration decreases and to inecrease its concentration, reaction will shift left.

C. Increase the pressure: If we Increase the pressure, then reaction will shft in a direction in which it is decreased.Since the pressure is directy proportional to the number of moles of gas. Thus, reactants has less pressure than products.Thus reaction will shift left to decrease it.

D. Remove CO₂ : If we remove it then reaction will shift right to increase its pressure again.

Hence , In case of A,B and C, reaction will shift left and in case D, it shifts right.

14. Reaction is: SO₂Cl_2(g)  +  energy  ⇄  SO_2(g)  +  Cl_2(g)

Reaction is endothermic reaction as energy is consumed. Thus, if temperature is decreased, then reaction will shift in which temperature is increased. So, reaction will shift in which we have energy so that temperature can increase. Thus, reaction will shift left. Thus, concentration of SO₂Cl₂ will increase and that of SO_{2(g) and} Cl_2(g) increase.

Thus, option A is correct.

15. Reaction is: CO_2(g)   +  H_2(g)  ⇄  CO_(g)  +  H₂O_(g)

Here H₂O is towards product. Thus, concentration of H₂O can be decreased if we add more of CO  in reaction as only then reaction will shift left to decrease its concentration. But if we add any of CO₂ or H₂ in reaction then the concentration will shift right ro decrease the concentration and concentration of H₂O will increase.

Hence, option C is correct.

16. Reaction is: C_(s)  +  2H_2(g)  ⇄ CH_4(g)  +  74 kJ

If we add solid C in reaction, then reaction will shift right to consume it. Thus the concentration of CH₄ increases and more of heat will be produced due to which temperature inecreases and that of H₂ decreases

Hence,option A,B and C is correct.

17. Reaction is: 2NO_(g)  +  Cl_2(g)  ⇄  2NOCl_(g)

Cl₂ is added then reaction will shift right to decrease its concentration and that of NO and CL₂ decreases.

Hence, option D is correct