Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 12-science Answered

how is the concept of coupling reactions useful in explaining the occurrence of non-spontaneous thermochemical reactions?
Asked by ganeshadode64 adode | 30 Oct, 2013, 12:34: PM
answered-by-expert Expert Answer

Coupling reactions:

Many reactions which are non-spontaneous (?G is +ve) can be made to occur spontaneously if these are coupled with reactions having larger negative free energy.

By coupling means both non-spontaneous and spontaneous reactions can be carried out simultaneously.

For example:

Decomposition of Fe2O3 into iron is a non-spontaneous reaction. However this decomposition can take place simultaneously if carbon monoxide is simultaneously burnt in oxygen.

                2Fe2O3 ? 4Fe + 3O2     ----- (1) ?G0 = +1487kJmol-1

             2CO + O2 ? 2CO2       -----      (2) ?G0 = - 514kJmol-1

Multiplying equation (2) by 3 and then adding to equation (1) we get

             6CO + 3O2 ? 6CO2        ?G0 = - 1543kJmol-1

                2Fe2O3     ? 4Fe + 3O2  ?G0 = +1487kJmol-1

-----------------------------------------------------------------------------------------------------

    2Fe2O3   + 6CO ? 4Fe   + 6CO2    ?G0 = -56.2Kjmol-1

Answered by Vaibhav Chavan | 30 Oct, 2013, 05:57: PM
CBSE 12-science - Chemistry
Asked by bhadauriyax | 30 Nov, 2023, 06:23: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by rahulbiswal946 | 08 Nov, 2023, 07:01: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by mishraridhi2020 | 23 Jun, 2022, 09:16: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by cjam41665 | 10 Oct, 2021, 12:56: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by arshbhatia0809 | 22 Jul, 2021, 09:47: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by amitkumar.cis | 14 Jan, 2021, 12:40: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by Surendersingh0493 | 18 Oct, 2020, 02:05: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by khandarev3580 | 10 Oct, 2020, 10:54: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by rchaitra1204 | 07 Sep, 2020, 09:43: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 12-science - Chemistry
Asked by dr.akanksha0411 | 07 Aug, 2020, 11:56: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
Get Latest Study Material for Academic year 24-25 Click here
×