titration q, on dilution (1 Viewer)

[LaCe]

a student first diluted 25ml of vinegar accurately to 100mL then titrated 10mL of the diluted solution with 0.097M of NaOH. titre was 17.2mL

I have the concentration of the diluted vinegar colution but how do i get the original concentration of the vinegar?

Thanks

 

[currysauce]

show ur working

 

[xiao1985]

find out how many moles of base is required to neutralise all acid... then u will know how many moles of acid there are in 10 ml of diluted acid... so u can know how many moles of acid are there in 100 ml of diculted acid = number of moles in undiluted 25ml of acid...

 

[Dreamerish*~]

did we need to know the titre?
because i can't seem to find a use for it in solving that question

 

[LaCe]

Are moles of solution in 100mL diluted = moles of undiluted 25mL solution ??

the question i really want to know is how does concentration change if u diluted it in water
ie. dilute 10ml of 0.24M solution to 100ml
or diltue 10ml of 0.24M in 100mL
(same thing?)

i have no idea about this dilution stuff

 

[Dreamerish*~]

Are moles of solution in 100mL diluted = moles of undiluted 25mL solution ??

the question i really want to know is how does concentration change if u diluted it in water
ie. dilute 10ml of 0.24M solution to 100ml
or diltue 10ml of 0.24M in 100mL
(same thing?)

i have no idea about this dilution stuff

yeah of course
if you have 100mLs of solution with say, 2 moles in it (very concentrated )
and you dilute it to 1000mL, there are still 2 moles in solution, because you're simply putting the 100mLs into 900mLs more water

but concentration changes of course

initially it was 2m/0.1L
and after dilution it becomes 2m/L

 

[LaCe]

Yeah of course...
Sry Im a bit hazy with some of the calculations in chem, but chem is mostly just regurgitation og info so that bit is easy.

 

[xiao1985]

dear D, if u dunno the titre, then how can u work out the amount of NaOH used to reach end/equivalence pt?!

so subsequently how can u figure out how many moles of acid there is?!