# chemistry desperately

posted by on .

i am completely lost, i confused myself.

i need to find the concentration of HC2H3O2

HC2H3O2 + NaOH ==> NaC2H3O2 + HOH

NaOH
C= 0.3 M
v= 0.25 L
n= 0.075 moles
M= 40.00g/mol
m= 3.00 g

NaC2H3O2
n= 0.075 moles
m= 0.4973 g(ammount of acetic acid in
solution)

HC2H302
v= 0.020 L
M= 60.06g/mol

thats all the information i have. i don't know how to calculate it. my friend said c1v1=c2v2 but i don't know what numbers id use

• chemistry desperately - ,

You are confused because you have too much information piled in together. You need to think this through. And you don't say what unit the concentration should be in.
M(NaOH) x L(NaOH) = mols NaOH.
mols NaOH = mols acetic acid since the equation is 1 mol NaOH to 1 mol acetic acid.

Now M(acid) x L(acid) = mols. You know mols, you know L acid (is that the 0.020 L), calculate M acid. That will be the molarity of the acetic acid in that 20 mL sample. By the way, I can't believe you used 0.25 L of the NaOH. That's 250 mL which is a huge volume to be titrated with. That means you would have had to refill a 50 mL buret five times. (Of course this could be a problem.)
I'm getting ready to leave for the night so if there is a quick question, please type it in before I leave.

• chemistry desperately - ,

alright thank you i think i should be able to figure it out. and i know we only did 3 trials though