A volume of x mL of 5 M $$NaHCO_{3}$$ solution was mixed with 10 mL of 2 M $$H_{2}CO_{3}$$ solution to make an electrolytic buffer. If the same buffer was used in the following electrochemical cell to record a cell potential of 235.3 mV, then the value of x=_______ mL (nearest integer).
$$Sn(s)|Sn(OH)_{6}^{2-}(0.5 M)|HSnO_{2}^{-}(0.05 M)|OH^{-}|Bi_{2}O_{3}(s)|Bi(s)$$
Consider upto one place of decimal for intermediate calculations