calculate the e.m.f (in V) of the cell:
`Pt|H_2(g)|BOH(Aq)"||"HA(Aq)|H_2(g)|Pt`,
0.1bar 1M 0.1M 1bar
Given : `K_a(HA)=10^(-7), K_b(BOH)=10^(-6)`

Options

A. `0.39` V
B. 0.36 V
C. 0.93 V
D. 0.63 V

Answer

A

Explanation

`E_(cell)=(0.06)/(2)log.([H^(+)]_(RHS)[P_(H_(2))]_(LHS))/([H^(+)]_(LHS)[P_(H_(2))]_(RHS)),becausealphaltlt1`
`{:([OH^(-)]_(LHS)=sqrt(k_(a)xxC)rArr10^(-3)),([H^(+)]_(LHS)=sqrt(KaxxC)=10^(=11)),([H^(+)]_(RHS)=sqrt(KaxxC)=10^(-4)):}`
`E_(cell)=(0.06)/(2)log.([10^(-4)]^(2)xx0.1)/((10^(-11))^(2)xx1)`
`E_(cell)=0.39V`