[ryan1180]

Hi, I have been working on a lab and one of the questions has stumped me.

I first had to calculate the molar mass of an acid in the form of HA(A=unknown)

10 M NaOH(.02235 L NaOH)=.0022 mol NaOH
Moles of acid=grams/MM
MM=grams/moles
(.225 g acid)/.0022 mol NaOH
MM=102.3 g

So I calculated that and then the question I'm having trouble with is "if the unknown acid is diprotic(H2A) how would the molar mass have been affected from the previous value obtained?"

I'm not sure about this as I can't directly see a connection between my previous calculations and the molar mass that I obtained, could anyone steer me in the right direction?

[sjb]

Hi, I have been working on a lab and one of the questions has stumped me.

I first had to calculate the molar mass of an acid in the form of HA(A=unknown)

10 M NaOH(.02235 L NaOH)=.0022 mol NaOH
Moles of acid=grams/MM
MM=grams/moles
(.225 g acid)/.0022 mol NaOH
MM=102.3 g

So I calculated that and then the question I'm having trouble with is "if the unknown acid is diprotic(H2A) how would the molar mass have been affected from the previous value obtained?"

I'm not sure about this as I can't directly see a connection between my previous calculations and the molar mass that I obtained, could anyone steer me in the right direction?

How do you know that the number of moles of acid is the same as the number of moles of NaOH in your initial calculation?

[masteroc]

I would double check your first calculation, as 10 (0.2235) =! .0022

Also, what does diprotic mean? Acid/Base questions are usually based on there being a 1:1 ratio of H to OH which allows you to make the assumption that your moles of OH will equal your moles of H. Once you look up the definition of diprotic, think about how that will change your ratio.