Answer:
4.03 x 10∧-3
Explanation:
The pH of the solution is 10.2, and we know:
pH + pOH = 14
pOH = 14 − pH
pOH = 14 − 10.2 = 3.8
pOH = −log[OH−]
3.8 = −log[OH−]
−3.8 = log[OH−]
[OH−] = 10∧−3.8 = 1.58 × 10∧−4
since NaOH(s) → Na∧+(aq) + OH∧−(aq), [NaOH] = 1.58×10−4.
627mL × 1L/1000mL × 1.58×10−4molesNaOH/1L × 40g NaOH/1mole NaOH
=4.03 × 10∧−3g NaOH
