The mass of sodium acetate $\left(\mathrm{CH}_3 \mathrm{COONa}\right)$ required to prepare $250 \mathrm{~mL}$ of $0.35 \mathrm{~M}$ aqueous solution is ________ g. (Molar mass of $\mathrm{CH}_3 \mathrm{COONa}$ is $82.02 \mathrm{~g} \mathrm{~mol}^{-1}$)