Buret Reading/ Titration Data

[Lyristes]

Sorry, for returning to this forum for help again, but my teacher is not exactly the best, and I'm not the brightest student.

Acid Initial Buret Reading (mL): 3.70
Acid Final Buret Reading (mL): 13.70

Base Initial Buret Reading (mL): 11.65
Base Final Buret Reading (mL): 23.55

The base, NaOH(aq), was 0.75 M, and I was supposed to find the molarity of acid based on this data.
Can someone please double check my work.

13.70 - 3.70 = 10.00 mL acid used

Since mol_acid = mol_base, then M_1 * V_1 = M_2 * V_2.

M_1 * 10.00 mL = 0.75M * 11.90 mL
M_1 = 0.8925 M acid

p.s. are my sig figs correct?

[ChenBeier]

Its correct. But I am wondering to have two times a buret. Normaly you have a sample (acid) in a beaker or Erlenmeyer flask and then you titrate using the Base with one buret.

The calculation is valid if the Acid is HA. If H₂A or H₃A then its different.

[Miaksoa]

The idea of having a twice is intriguing to me. The standard procedure involves placing an acid sample in a beaker or Erlenmeyer flask and titrating with the base using a single buret.

[ChenBeier]

That is what I am already said. Why repeating?