Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

The factor of  ΔG values is important in metallurgy.  The ΔG  values for the following reactions at 8000C  are given as follows.
S2(s)+2O2(g)2SO2(g):ΔG=544  kJ
2Zn(s)+S2(s)2ZnS(s):ΔG=293  kJ
2Zn(s)+O2(g)2ZnO(s):ΔG=480  kJ
The ΔG for the reaction 2ZnS(s)+3O2(g)2ZnO(s)+2SO2(g)  will be  (kJ)

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

answer is -731.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

detailed_solution_thumbnail

Calculation of ΔG for Reaction in Metallurgy

The question involves determining the ΔG value (Gibbs free energy change) for the reaction: 
2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g)
using the given ΔG values for related reactions. The ΔG value is an important factor in metallurgy as it determines the feasibility of a reaction.

Concept: To calculate the ΔG value of a reaction, we use the principle of Hess's Law, which states that the total ΔG for a reaction can be calculated by adding or subtracting the ΔG values of individual reactions that combine to give the overall reaction. The given reactions and their ΔG values are: 
Reaction 1: S2(s) + 2O2(g) → 2SO2(g); ΔG = -544 kJ
Reaction 2: 2Zn(s) + S2(s) → 2ZnS(s); ΔG = -293 kJ
Reaction 3: 2Zn(s) + O2(g) → 2ZnO(s); ΔG = -480 kJ

Steps to Calculate ΔG:

  1. The target reaction is: 
    2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g).
  2. We combine the given reactions to form the target reaction:
    • From Reaction 1, we get 2SO2(g). This is used directly, so: 
      ΔG1 = -544 kJ.
    • From Reaction 2, 2ZnS(s) is formed, but we need to reverse this reaction to use 2ZnS(s) as a reactant: 
      Reversing Reaction 2 gives: 
      2ZnS(s) → 2Zn(s) + S2(s); ΔG = +293 kJ.
    • From Reaction 3, 2Zn(s) reacts with O2(g) to form 2ZnO(s). This is used directly, so: 
      ΔG3 = -480 kJ.
  3. Add up the ΔG values to get the total ΔG for the target reaction: 
    ΔG = ΔG1 + ΔG3 - ΔG2.
  4. Substituting the values: 
    ΔG = (-544) + (-480) + (+293) = -731 kJ.

Final Answer: The ΔG for the reaction 2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g) is -731 kJ.

Question Image
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring