A soft drink was bottled with a partial pressure of CO _ 2 of 3 bar...

A soft drink was bottled with a partial pressure of ${CO}_{2}$ of 3 bar over the liquid at room temperature. The partial pressure of ${CO}_{2}$ over the solution approaches a value of 30 bar when $44g$ of ${CO}_{2}$ is dissolved in $1kg$ of water at room temperature. The approximate $pH$ of the soft drink is ___________$\times {10}^{- 1}$.
(First dissociation constant of ${H}_{2}{CO}_{3} = 4 . 0 \times {10}^{- 7}; \log 2 = 0 . 3;$ density of the soft drink $= 1g{mL}^{- 1}$)