[ch3mg1rl]

Hey everyone,

I'm having a bit of difficulty with this question from a past lab experiment. The purpose was to determine the concentration of a NaOH solution, then use that solution to determine the value of Ka for a weak acid.

Here's the question:

Based on the results for Part I: calculate the concentration of NaOH in each sample and the average concentration of NaOH. Potassium hydrogen phthalate is a monoprotic acid with a molecular mass of 204.23 g/mol.

Here's some data:

Mass-
Potassium hydrogen phthalate = 0.462 g
NaOH = 2.97 g

Volume-
14.82 mL NaOH

What I tried:

I set up the problem using dimensional analysis, but I'm not too sure this is the correct method...

0.462g KHP x (1 mol KHP/204.23g KHP) = 0.00226 mol KHP

0.00226 mol KHP / ? (I'm stuck here because the volume is in terms of NaOH)

Can someone explain to me how to obtain the correct concentration...? Thanks.

[Borek]

http://www.titrations.info/titration-calculation

[ch3mg1rl]

I think i got it. thanks