Answer:
47.7 mL
Explanation:
There is some info missing. I think this is the original question.
A chemistry student weighs out 0.306 g of citric acid (H₃C₆H₅O₇), a triprotic acid, into a 250. mL volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.1000 M NaOH solution. Calculate the volume of NaOH solution the student will need to add to reach the equivalence point. Be sure your answer has the correct number of significant digits.
First, let's calculate the moles of citric acid (MW 192.12 g/mol).
0.306 g × (1 mol/192.12 g) = 1.59 × 10⁻³ mol
Let's consider the neutralization reaction between H₃C₆H₅O₇ and NaOH.
H₃C₆H₅O₇ + 3 NaOH → Na₃C₆H₅O₇ + 3 H₂O
The molar ratio of H₃C₆H₅O₇ to NaOH is 1:3. The moles of NaOH are 3 × 1.59 × 10⁻³ mol = 4.77 × 10⁻³ mol
The volume of 0.1000 M NaOH solution that contains 4.77 × 10⁻³ moles is:
4.77 × 10⁻³ mol × (1000 mL/0.1000 mol) = 47.7 mL
