Q. 264.2( 10 Votes )

Which of the following reactions will get affected by increasing the pressure? Also, mention whether change will cause the reaction to go into forward or backward direction.

(i) COCl2 (g) CO (g) + Cl2 (g)

(ii) CH4 (g) + 2S2 (g) CS2 (g) + 2H2S (g)

(iii) CO2 (g) + C (s) 2CO (g)

(iv) 2H2 (g) + CO (g) CH3OH (g)

(v) CaCO3 (s) CaO (s) + CO2 (g)

(vi) 4 NH3 (g) + 5O2 (g) 4NO (g) + 6H2O(g)

Answer :

According to Le Chatelier’s principle, an increase in pressure applied to the system at equilibrium favours the reaction in the direction which takes place with a decrease in a total number of moles. If there is no change in the number of moles of gases in a reaction, a pressure change does not affect the equilibrium.


Hence, reactions affected will be those in which number of moles of products (np) is not equal to number of moles of reactants (np )


np ≠ nr. Hence, the reactions (i), (iii), (iv), (v) and (vi) will be affected. By applying Le Chatelier’s principle, we can predict the direction. In general,


The reaction will go to the left if np > nr


The reaction will go tp the right if np < nr


(i)COCl2 (g) CO (g) + Cl2 (g)


Number of moles of products (np)= 2


Number of moles of reactants (nr) = 1


np > nr


According to Le Chatelier’s principle, the reaction will proceed in the backward reaction.


(ii) CH4 (g) + 2S2 (g) CS2 (g) + 2H2S (g)


Number of moles of products (np)= 3


Number of moles of reactants (nr) = 3


np = nr


According to Le Chatelier’s principle, the reaction will not be affected by the pressure.


(iii) CO2 (g) + C (s) 2CO (g)


Number of moles of products (np)= 2


Number of moles of reactants (nr) = 1


np > nr


According to Le Chatelier’s principle, the reaction will proceed in the backward direction.


(iv) 2H2 (g) + CO (g) CH3OH (g)


Number of moles of products (np)= 1


Number of moles of reactants (nr) = 3


np < nr


According to Le Chatelier’s principle, the reaction will proceed in the forward direction.


(v) CaCO3 (s) CaO (s) + CO2 (g)


Number of moles of products (np)= 2


Number of moles of reactants (nr) = 1


np > nr


According to Le Chatelier’s principle, the reaction will proceed in the backward direction.


(vi) 4 NH3 (g) + 5O2 (g) 4NO (g) + 6H2O(g)


Number of moles of products (np)= 10


Number of moles of reactants (nr) = 9


np > nr


According to Le Chatelier’s principle, the reaction will proceed in the backward direction.


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Chemical Equilibrium | Basic introductionChemical Equilibrium | Basic introductionChemical Equilibrium | Basic introduction58 mins
Full Chapter Quiz | Chemical Equilibrium | Check your learningFull Chapter Quiz | Chemical Equilibrium | Check your learningFull Chapter Quiz | Chemical Equilibrium | Check your learning57 mins
Chemical Equilibrium Lecture 4Chemical Equilibrium Lecture 4Chemical Equilibrium Lecture 438 mins
Chemical EquilibriumChemical EquilibriumChemical Equilibrium44 mins
Ionic Equilibrium Lecture 5Ionic Equilibrium Lecture 5Ionic Equilibrium Lecture 541 mins
Complete Revision of Chemical EquilibriumComplete Revision of Chemical EquilibriumComplete Revision of Chemical Equilibrium43 mins
Law of Chemical Equilibrium | Concepts at fingertipsLaw of Chemical Equilibrium | Concepts at fingertipsLaw of Chemical Equilibrium | Concepts at fingertips50 mins
Le Chatelier's PrincipleLe Chatelier's PrincipleLe Chatelier's Principle34 mins
Hydrolysis of Strong Acid & Weak BaseHydrolysis of Strong Acid & Weak BaseHydrolysis of Strong Acid & Weak BaseFREE Class
Understanding pH | Part 1Understanding pH | Part 1Understanding pH | Part 156 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses