November 13, 2024, 01:26:24 AM
Forum Rules: Read This Before Posting


Topic: *URGENT* Prac Lab test % by mass of mixture by titration  (Read 19634 times)

0 Members and 1 Guest are viewing this topic.

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #15 on: June 27, 2006, 10:08:26 AM »
No Iam not sure , hopefully its is in a solid form though. Thankyou for you help.

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #16 on: June 27, 2006, 10:18:53 AM »
thanks i get most of it now. but just one last question..
once i have done the titrations how do i use the titration infomation to find the mass of the Na2CO3

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27843
  • Mole Snacks: +1812/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #17 on: June 27, 2006, 10:32:51 AM »
thanks i get most of it now. but just one last question..
once i have done the titrations how do i use the titration infomation to find the mass of the Na2CO3

As Alberto wrote: you start with the reaction equation.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #18 on: June 27, 2006, 11:00:11 AM »
Could you please enlighten me on this particular equation and how i use it to find the mass form the titration results.

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #19 on: June 27, 2006, 11:09:39 AM »
Is there any chance of a response ,Please since is it 1am where i live and iam very tired ,thankyou.

ANYone please..!! I am realy in need of some sleep.
« Last Edit: June 27, 2006, 11:25:44 AM by lachie123 »

Offline Alberto_Kravina

  • Assault Chemist
  • Retired Staff
  • Full Member
  • *
  • Posts: 608
  • Mole Snacks: +70/-15
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #20 on: June 27, 2006, 12:32:32 PM »
The reaction equation is written in the link that Borek posted, only that only the acid (in your case hydrochloric) is written as "H+" and the carbonate (in your case sodium carbonate) is written as "CO32-". Also, it is explained that one mole of carbonate requires two moles of acid (assuming that you use a monoprotic acid like in your case) which should make clear how to calculate the mass of sodium carbonate afterwards.

Hint for alculations: At equivalence point: neq(Na2CO3) = neq(HCl)

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #21 on: June 28, 2006, 04:48:18 AM »
i titrated the mixture and the teacher let us do the calculations at home.

My mass of mixture was 8.89g
and my disovled mixture volume was made up to 500mls
my Aliquot volume used was 20 mls

I used methol Orange as a indicator and my average amount of 0.2 mole HCl used to titrate was 7.35 mls.

How do i now use this info to find the mass of Na2CO3 so i can find the mass of the NaCL

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27843
  • Mole Snacks: +1812/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #22 on: June 28, 2006, 05:08:04 AM »
How do i now use this info to find the mass of Na2CO3 so i can find the mass of the NaCL

Alberto pointed out to you all necessary information.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #23 on: June 28, 2006, 05:39:39 AM »
I can't understand the infomation , could someone please help me understand the process a little more clearly.. ???

Offline xiankai

  • Chemist
  • Full Member
  • *
  • Posts: 785
  • Mole Snacks: +77/-37
  • Gender: Male
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #24 on: June 28, 2006, 06:06:09 AM »
based on the reaction

2 HCl + Na2CO3 --> H2O + 2 NaCl
OR
2H3O+ + CO32- --> H2O

mole ratio is

2HCl ? Na2CO3

assuming all the Na2CO3 reacted
assuming titration end-point was reached accurately

we can conclude the reaction took place in exact mole ratio as described above.

given the moles of HCl that reacted, you can find the moles of Na2CO3 that reacted, based on mole ratio.

since mass of mixture = mass of Na2CO3 + mass of NaCl

mass of NaCl = mass of mixture - mass of Na2CO3

it cant get any simpler, i hope
one learns best by teaching

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #25 on: June 28, 2006, 06:07:35 AM »
thanks for that dude. :)  THAT HELPED ME SOOO MUCH.  everyone give xiankia a heap of scooby snacks he deserves them.!!! ;D
« Last Edit: June 28, 2006, 06:23:40 AM by lachie123 »

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #26 on: July 02, 2006, 12:12:08 PM »
Who the f&#$ gavew me a negitive scoob snack , if i ever see u i will stick a 1L conical flask up your ass backwards.

Offline DrCMS

  • Chemist
  • Sr. Member
  • *
  • Posts: 1306
  • Mole Snacks: +212/-84
  • Gender: Male
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #27 on: July 03, 2006, 05:35:27 AM »
I just took one from you for being an annoying little sod. 

People tried to help you but you just wanted somebody to do it for you and eventually xiankai took pity on you and did it all for you. 

This forum is not here so lazy people can get their homework done for them it's here to show you how to do it.

Feel free to email me for my address and we can have a chat about that flask.

Offline lachie123

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +0/-7
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #28 on: July 03, 2006, 06:30:55 AM »
Give me a break , u [...] , i failed theĀ  test anyway ( my results were not accuarte enough)
« Last Edit: July 03, 2006, 07:10:20 AM by Borek »

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27843
  • Mole Snacks: +1812/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: *URGENT* Prac Lab test % by mass of mixture by titration
« Reply #29 on: July 03, 2006, 07:05:03 AM »
Give me a break , u [...] , i failed the  test anyway ( my results were not accuarte enough)

Topic locked, 5 days ban.
« Last Edit: February 13, 2010, 08:20:29 AM by Borek »
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Sponsored Links