1. How many milliliters of 0.500 M NaOH should be added to a flask that containing 10.0g of tris hydrochloride(157.60 g/mol)to give a buffer of pH 7.60 in a final volume of 250 mL？(10分)

2. Please use charge balance and mass balance to prove the [H_{3}O^{+}] of Na_{2}HPO_{3 }(with a formal concentration of *F*)in solution is equal to . (10分) [H_{3}O^{+}] = (*K_{2}* and *K_{3}*_{ }are the dissociation constant of NaH_{2}PO_{3} and Na_{2}HPO_{3})