Register to reply

Chemsitry - Moles Consumed

by wcbryant87
Tags: chemsitry, consumed, moles
Share this thread:
wcbryant87
#1
Apr20-09, 04:49 PM
P: 14
1. The problem statement, all variables and given/known data

The overall chemical equation for the titration reaction is:
OCl(aq) + 2 S2O3(aq) + 2H+(aq) 6 Cl(aq) + S2O6(aq) + H2O(R)

If a titration requires 5.29 ml 0.256 M Na2S2O3,
(i) how many moles of S2O32&(aq) were consumed in the titration, and
(ii) how many moles of OCl&(aq) were in the sample?


2. Relevant equations



3. The attempt at a solution

Ok so what i did was take .245/52.9 and multiplied it by 2 to get .0096 moles of S2O3 consumed....is that right?
Phys.Org News Partner Science news on Phys.org
Flapping baby birds give clues to origin of flight
Prions can trigger 'stuck' wine fermentations, researchers find
Socially-assistive robots help kids with autism learn by providing personalized prompts
Borek
#2
Apr21-09, 10:13 AM
Admin
Borek's Avatar
P: 23,578
No.

Try to explain what you did and why.

And using numbers that were given in the question won't hurt.
wcbryant87
#3
Apr21-09, 04:22 PM
P: 14
I just realized there is supposed to be an arrow in between the 2H and the Cl; that is where the equation splits into reactants and products.

I'm looking over it again and trying something different. I messed up in the math the first go around

.256/.00529 L = 48.4 mols X 2 (because there are 2 mols S2O3) and that gives me 96.8 mols S2O3; part i

Shouldn't part (ii) just be the 48.4 mols from the previous?

Borek
#4
Apr21-09, 05:01 PM
Admin
Borek's Avatar
P: 23,578
Chemsitry - Moles Consumed

You are still wrong. Check your units.
wcbryant87
#5
Apr21-09, 05:11 PM
P: 14
M = mols/volume

I know M and the volume, so it should be M * volume..not divided..right?

.256 * .00529 = .00135

.00135 * 2 = .0027 mols. Is that right?
Borek
#6
Apr21-09, 05:33 PM
Admin
Borek's Avatar
P: 23,578
Better, but still wrong. You got concentration&volumes&moles part right. Why do you multiply by two if you are calculating number of moles of S2O32-?
wcbryant87
#7
Apr21-09, 06:38 PM
P: 14
I multiplied by 2 because there are 2 S2O3 in the equation. Doesn't that mean you multiply it by two so that your ratio is correct?
Borek
#8
Apr22-09, 12:35 PM
Admin
Borek's Avatar
P: 23,578
Think about it - you put a mole of substance into the baker, but as reaction equation have a 2 in the equation, that means you put 2 moles in the baker? That's what you did now.


Register to reply

Related Discussions
Energy consumed to create force Classical Physics 8
Least fuel consumed from point A to B with no time constraint Mechanical Engineering 7
What would happen if I were to near and be consumed by a black hole? Astronomy & Astrophysics 1
Recommendations on Organic Chemsitry - Intro or otherwise Science & Math Textbooks 4
100 Calories consumed/mile? General Physics 3