Question

A 29.00 mL sample of an unknown H3PO4 solution is titrated with a 0.130 M NaOH solution. The equivalence point is reached when 27.73 mL of NaOH solution is added.

Answer 1

The student's question involves a chemistry problem where they need to calculate the unknown concentration of a phosphoric acid solution after titrating it with a known concentration of sodium hydroxide.

Step-by-step explanation:

The question is about the titration of an unknown concentration of phosphoric acid (H3PO4) with a known concentration of sodium hydroxide (NaOH). To find the concentration of the phosphoric acid solution, we can use the information given: the volume of the acid solution (29.00 mL), the concentration of the NaOH solution (0.130 M), and the volume of NaOH solution used to reach the equivalence point (27.73 mL).

To calculate the molarity of the H3PO4 solution, we would use the formula:

M1 × V1 = M2 × V2

Where M1 is the molarity of the H3PO4 solution, V1 is the volume of the H3PO4 solution, M2 is the molarity of the NaOH solution, and V2 is the volume of the NaOH used at the equivalence point.

Answer 2

I am first assuming that you want the molarity of the acid. Use the formula
`M_(a) V_(a) = M_(b)V_(b)` which is the titration formula. M is molarity (a is of acid and b is of base) and V is volume in mL (a is of acid and b is of base). Plugging in gives us
`(29 mL)(M_(a)) = (0.130 M)(27.73 mL)`. Solving gives us
`M_(a) = 0.124 M`