The EMF of the following concentration cell is 0.72 V. Pt|H2(1atm)|KOH(0.1M)||HCl(0.48M)|H2(1atm),Pt. Assuming that KOH is 85% ionized, if the ionic product of water is 2.55×10−x, the value of x is.............
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Solution
KOH0.1M⇌K⊕−+⊖OH− KOH is 85% ionizable. ⇒[⊖OH]=0.1×0.85=0.085M [H⊕]=Kw[⊖OH]=c1(say) Anode :12H2→H⊕(c1)+e− Cathode : H⊕+e−→12H2 Ecell=0.72V ⇒0.72=−0.0591logc10.48 ⇒−0.720.059=logKw0.085×0.48 ⇒Kw=2.55×10−14 so value of x is 14.