Answer:
0.362 g of weak acid was used for titration
Explanation:
Let's assume the weak acid (HA) is monobasic.
Balanced equation: [tex]HA+NaOH\rightarrow NaA+H_{2}O[/tex]
So, 1 mol of NaOH neutralizes 1 mol of HA
Number of moles of NaOH in 34.65 mL of 0.0994 M of NaOH = [tex]\frac{0.0994\times 34.65}{1000}moles=0.00344moles[/tex]
So, 0.00344 moles of NaOH neutralizes 0.00344 moles of HA
So, the student used 0.00344 moles of acid for titration.
So, mass of acid was used = [tex](105.125\times 0.00344)g=0.362g[/tex]