Calculate the minimum weight of NaOH required to be added in R H S to consume all the H+ - Chemistry - Electrochemistry

Question

Calculate the minimum weight of NaOH required to be added in R H S
to consume all the H+ present in R H S of cell of e m f +0 701 V at
25°C before its use Also report the e m f of cell after
addition of NaOH [Zn/Zn^+2 (0 1M) //HCl(1L) /H2(g),Pt]
E°Zn/Zn^+= +0 76V

Geetha · Accepted Answer

The redox reactions areZn →Zn2+ + 2 e-2 H+ + 2 e- → H2ECell = EZn/Zn2+0 - 0
05912 log [Zn2+][H+]20
701      = 0
760 +  0
05912 log [H+]2[Zn2+]         = 0
760 +  0 05912 log [H+]2[0
1][H+] = 0
0316 mol / LMilliequivalent of NaOH = Milliequivalent of H+W40 × 1000 = 0
0316 × 1000W = 1
264 gThus weight of NaOH added = 1
264 gAfter addition of NaOH the H+ ion concentration = 10-7New emf isE      = 0
760 +  0
05912 log [H+]2[Zn2+]    = 0
760 +  0 05912 log [10-7]2[0
1]Ecell = 0 3765 V

Calculate the minimum weight of NaOH required to be added in R.H.S. to consume all the H+ present in R.H.S. of cell of e.m.f. +0.701 V at 25°C before its use. Also report the e.m.f. of cell after addition of NaOH. [Zn/Zn^+2 (0.1M) //HCl(1L) /H2(g),Pt]. E°Zn/Zn^+= +0.76V.