Titration Question

[1070752]

I'm completely stuck on this, not sure how to go about solving it. Any help would be appreciated.

1. 40 mL of 0.10 M H3PO4 are mixed with 5 mL of 0.20 M NaOH and the mixture brought
up to a total volume of 100 mL with distilled water. (pKas for phosphoric acid are: 2.1,
6.7 and 12.3)

a) What is the pH of the resulting solution?

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[super frank]

I don't have access to a pen/paper right now, but perhaps solve for what is in excess (mol) and then use that to calculate the pH (depends on what's in excess, pOH, etc.). The uncertainty lies in how deprotonated the phosphoric acid becomes for the N1V1 = N2V2 calculation...