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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: aaronstonedd on April 19, 2013, 12:32:50 PM

Title: Numerical regarding the Law of Constant Composition
Post by: aaronstonedd on April 19, 2013, 12:32:50 PM
The numerical in it's full glory:
10 mL (sic) of hydrogen combine (sic) with 5 mL (sic) of oxygen to yield water. When 200 mL (sic) of hydrogen at NTP are (sic) passed over heated CuO, the latter loses 0.144 g of its mass. Do these results agree with the law of constant composition?

Title: Re: Numerical regarding the Law of Constant Composition
Post by: Borek on April 19, 2013, 12:51:01 PM
H2 (sic) and O2 (sic).

Apparently you should check if the oxygen/hydrogen proportion is identical in each case (sic).
Title: Re: Numerical regarding the Law of Constant Composition
Post by: opsomath on April 19, 2013, 02:15:46 PM
Dear OP, I think you have fallen afoul of Muphry's Law in your use of "it's" and your many, many uses of "sic".

It isn't correct to ask the internet for a step by step procedure to figure out your results; part of the question is whether you can figure that out, I think.

So, let me ask you this in turn; what chemical reaction is going on here? Write its balanced equation.
Title: Re: Numerical regarding the Law of Constant Composition
Post by: Arkcon on April 19, 2013, 02:31:17 PM
I think you can assume that H2 and O2 are being used.  These gasses are diatomic, we can't "pass over" or "combine" H and O.  Those may be used to visualize reactions, but they're not things we can measure.  A tank full of hydrogen or oxygen, we can measure those as full or empty, and they'll contain diatomic gasses.