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The e.m.f of a cell corresponding to the reaction `Zn+2H^(+)(aq)toZn^(2+)(0.1M)+H_(2)(g)`(1 atm) is 0.26 volt at `25^(@)C`.Calculate the pH of the solution at the hydrogen electrode. |
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Answer» Correct Answer - 9 `E_(cell)^@=0.76` volt Applying nearest equation `E_(cell)=E_(cell)^@(-0.0591)/2"log"([Zn^(2+)][P_(H_2)])/([H^+]^2), " " 0.26=0.76(-0.0591)/2"log"((0.1)(1))/([H^+]^2)` log `0.1/([H^+]^2)=(2xx0.50)0.0591` or log 0.1-log `[H^+]^2=17` or 2pH=17-log 0.1 pH=`18/2=9` |
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