The e.m.f of the cell : `H_2(g)` |Buffer | Normal calomel electrodes is 0.6885 volt at ` 25^(@)C `, when barometric pressure is 760 mm Hg. What is the pH of the buffer solution ? Given `E_("calomel")^(@) = 0.28` volt

Answer

7

Explanation

`E_("cell") = E_("cell")-(0.0591)/(n) logCl , 0.6885 =0.28 - (0.0591)/(2) log[H^(oplus)]^(2)`
`log[H^(oplus)]^(2)=(-(0.6885 - 0.28) xx 2)/( 0.0591) , 2 og(H^(oplus)) = -13.824`
`log(H^(oplus)) = (-13.824)/(2) , P^(H) = - log(H^(oplus)) = (13 - 824)/(2) = 6.912 ~=7 , P^(H) = 7`