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Offline curiousgeorge1234

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Calculation question
« on: November 05, 2006, 11:00:23 AM »
I know this is extremely easy, but I'm getting confused   :'(

I am trying to determine the % of Cl in AgCl.  I have found two equations that can give me this answer.  However, both give me different answers, although I know they are related.  I think one answer is giving me Ag % and the other Cl %, but not sure which is which.

% Cl in sample = (mass Cl- / mass sample) x 100
 0.1204 / 0.3212 x 100
 37.48 %

OR

    Mass of unknown chloride after drying: 0.1204 g
    Mass of sample: 0.3212 g
    One mole of AgCl contains one mole of Cl-. Therefore:
    (0.3212 g AgCl) / (143.32 g/mol) = 2.2 x 10-3 mol AgCl
    (2.2 x 10-3 mol AgCl) x (35.45 g/mol Cl) = 0.079 g Cl
    (0.079 g Cl) / (0.1204 g sample) x 100% = 65.99% Cl in unknown chloride sample

Offline Borek

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Re: Calculation question
« Reply #1 on: November 05, 2006, 12:17:55 PM »
% Cl in sample = (mass Cl- / mass sample) x 100
0.1204 / 0.3212 x 100

Quote
Mass of unknown chloride after drying: 0.1204 g
Mass of sample: 0.3212 g

Quote
(0.079 g Cl) / (0.1204 g sample) x 100% = 65.99% Cl in unknown chloride sample

What is sample, what is unknown chloride, what is silver chloride, what is Cl-, what is what of what? I think you are mixing completely different things in calculations. Describe precisely whole procedure.
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