[astuart]

I have a question that I don't know where I'm supposed to begin to start solving it.  I've solved similar questions in the past but am just having a mind blank...

a 20mL pipette was used to deliver a volume of HCl to a flask that was titrated against NaOH.  The concentration of NaOH was 0.1051 +- 0.0004M.  The volume of NaOH delivered form the burette was 20.65 +- 0/05m.  Calculate the concentration of HCl and its uncertainty.

The uncertainty factor is throwing me off here, and I don't know how to actually solve it.

Any tips in the right direction?

*MOD Edit: put question in title*

[EpicWinston]

What was the original volume of HCl? did the solution change color (pinkish)

[astuart]

I'm not sure, the question doesn't specify - I'm only given the information above.

If anything, I assume I would have to convert the volume of NaOH to mols of NaOH, then convert that amount of moles to moles of HCL, then to grams of HCL.  Still not sure if that's the right track though.

[outman]

perhaps need to consider the  "Propagation of deviation" of multiplication and division.

but i still don't know the  deviation of the 20 ml pipette.

[Borek]

Technically speaking it should depend on the glass class:

http://www.titrations.info/pipette-burette

so you can write "I am assuming class A pipette" and follow from there.

[curiouscat]

I was thinking calculate the extremes based on uncertainty i.e. 0.1051 + 0.0004M and 0.1051 - 0.0004M

Same for volumes.

Now, based on all combinations (4) of conc. and volume what range of conc. of HCl do you get?

That max. range is your uncertainty.