Urgent help needed (1 Viewer)

leesh95

Member
Joined
Nov 7, 2011
Messages
487
Gender
Undisclosed
HSC
2013
For our prac exam we are titrating NaOH with oxalic acid. This will then be used to titrate acetic acid.

According to the steps our teacher gave us each student had to make a NaOh solution by mixing 2g of NaOH in 500 mL water. This is then titrated.

Unfortunately when I was doing my prac I spilled a lot of my NaOH solution. I have only done one titration with oxalic acid and I don't think I have enough solution left.

The problem is that the if I make a new NaOH solution I won't have enough time to standardize it.

Is it possible that I dilute my NaOH solution with water to increase it's volume and then titrate it with oxalic acid. Will doing this affect my titration result of acetic acid?
 
Last edited:

leesh95

Member
Joined
Nov 7, 2011
Messages
487
Gender
Undisclosed
HSC
2013
Need urgent chem help

For our prac exam we are titrating NaOH with oxalic acid. This will then be used to titrate acetic acid.

According to the steps our teacher gave us each student had to make a NaOh solution by mixing 2g of NaOH in 500 mL water. This is then titrated.

Unfortunately when I was doing my prac I spilled a lot of my NaOH solution. I have only done one titration with oxalic acid and I don't think I have enough solution left.

Is it possible that I dilute my NaOH solution with water to increase it's volume and then titrate it with oxalic acid. Will doing this affect my titration result of acetic acid?
 

Immortalp00n

Member
Joined
Dec 27, 2012
Messages
272
Gender
Undisclosed
HSC
2009
Re: Need urgent chem help

i think u will need to make up another solution
coz now ur solution isnt a solution of 2g NaOH and 500ml distilled water

its possibly 1g NaOH and 300 mL distilled water, so u will get messed up results.
and u cant just refill it with water coz then it will decrease in concentration due to the loss of NaOH

TLDR, gotta make a new standard solution
 

leesh95

Member
Joined
Nov 7, 2011
Messages
487
Gender
Undisclosed
HSC
2013
Re: Need urgent chem help

No the NaOH wasn't a standard solution. It had to be standardized by titrating with Oxalic acid standard solution. Then when we found out the concentration of NaOH we use it to titrate acetic acid.

So adding water to NaOH and fiding new concentration by titration won't work?
 

golgo13

Alchemist
Joined
Feb 12, 2009
Messages
304
Gender
Male
HSC
2011
Re: Need urgent chem help

It could but it'd be a lot more work than just to make another set of NaOH solution and then to standardise that, because ur gonna need quite a bit of it for the acetic acid if i'm reading it correctly
 

leesh95

Member
Joined
Nov 7, 2011
Messages
487
Gender
Undisclosed
HSC
2013
Re: Need urgent chem help

Well I have about 200 mL now so if I add another 200 I would probably get 400 mL.

You only need 20 mL for titrating with oxalic acid but the NaOH is then used to titrate acetic acid. I'm afraid I won't have enough solution of NaOH left to titrate acetic acid.
 

Immortalp00n

Member
Joined
Dec 27, 2012
Messages
272
Gender
Undisclosed
HSC
2009
Re: Need urgent chem help

No the NaOH wasn't a standard solution. It had to be standardized by titrating with Oxalic acid standard solution. Then when we found out the concentration of NaOH we use it to titrate acetic acid.

So adding water to NaOH and fiding new concentration by titration won't work?
ohhh i see
and even then i dont think it'll work ( btw this water u r referring to must be distilled( minimal impurities and shit) u know yeh)
 

leesh95

Member
Joined
Nov 7, 2011
Messages
487
Gender
Undisclosed
HSC
2013
Re: Need urgent chem help

Also it's not NaOH concentration we get marked on it's how accurate our acetic acid results are.
 

someth1ng

Retired Nov '14
Joined
Sep 18, 2010
Messages
5,558
Location
Adelaide, Australia
Gender
Male
HSC
2012
Uni Grad
2021
I'm assuming your oxalic acid solution is the primary standard.

Technically, you CAN do that but note that titration revolved around the number of moles that react. If you dilute too much, you might only be able to titrate against a tiny sample of acetic acid, making it inaccurate since measuring errors will become more significant.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top