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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: LMI25803 on November 12, 2017, 03:50:30 PM

Title: Titration of Motor Oil
Post by: LMI25803 on November 12, 2017, 03:50:30 PM
TITRATION of Motor Oil
SAMPLE
Iodine: 90g
Pyridine: 264g
Solvent: 604g
Water: 25 ml

Total volume
of solution
971 ml

usage
of solution
5.161 ml

I have to assign WATER QUANTITY
IN THE POLLUTED SAMPLE
and chemical equation which is here --> https://imgur.com/a/dmBOX (https://imgur.com/a/dmBOX) in blankly square i need to assign a numbers i think , do i need viscosity ?

i have no knowledge in chemistry cuz im not on that school where we learning this ...
Any ideas ?

Title: Re: Titration of Motor Oil
Post by: Borek on November 12, 2017, 05:02:48 PM
As with every titration problem it is just about following the stoichiometry of the reaction. What you are given is reaction equation, it requires balancing before it can be used.

Outline of the general calculation method is here: http://www.titrations.info/titration-calculation
Title: Re: Titration of Motor Oil
Post by: LMI25803 on November 12, 2017, 06:28:59 PM
TY for the answer ... Should i care about this https://imgur.com/a/x931G (https://imgur.com/a/x931G) ?

Can it be right ? I2+SO2+H2O+CH2OH+3B=3BH(+)+2I(-)+CH3OSO3(-)
Title: Re: Titration of Motor Oil
Post by: Borek on November 13, 2017, 03:54:22 AM
Quote from: LMI25803 on November 12, 2017, 06:28:59 PM
TY for the answer ... Should i care about this https://imgur.com/a/x931G (https://imgur.com/a/x931G) ?

Depends on what you mean by "not caring". B (which apparently stands for pyridine) is present there just to consume produced H+, so the reaction that has to be balanced can be written either as

I2 + SO2 + H2O + CH2OH + B :rarrow: BH+ + I- + CH3OSO3-

or as

I2 + 2SO2 + H2O + CH2OH :rarrow: H+ + I- + CH3OSO3-

and both will give exactly the same stoichiometry (it is called Karl Fischer titration by the way).

Quote
Can it be right ? I2+SO2+H2O+CH2OH+3B=3BH(+)+2I(-)+CH3OSO3(-)

I am afraid not - for the reaction equation to be balanced you need exactly the same number of atoms and exactly the same charge on both sides of the equation. Count hydrogen atoms on both sides.

Note: you can use symbols (placed right above the edit field) to correctly format your equations, it makes them much easier to read.
Title: Re: Titration of Motor Oil
Post by: LMI25803 on November 13, 2017, 05:25:39 AM
I got this I2+2SO2+2H2O+2CH3OH=H+I2+2CH3OSO3

Or

I2+2SO2+2H2O+2CH3OH+6B=6BH+2I+2CH3OSO3

or

I2+2SO2+2H2O+2CH3OH=H+2I+2CH3OSO3

if not i have really no idea