Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: hwylee on September 04, 2008, 12:52:03 AM
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Three compounds D,E, and F all contain element G. The percent by weight of the element G in each of the compounds was determined by analysis. The experimental data are presented on the following:
Compound: % weight of G: Molecular weight of compound
D 53.9 131.7
E 64.2 165.9
F 47.7 74.5
a) What is the most likely value for the atomic weight of element G?
I tried to get the difference of the three given weights, which result to be 36g. However, i doubt that it is the most likely value for G.
b) Compund F containes carbon, hydrogen, and element G. When 2.19g of compound F is completely burned in oxygen gas, 3.88g of carbon dioxide gas and 0.80 g of water is produced. What is the most likely formula for compund F?
I tried using the law of conservation of mass. F=2.19g 02=2.49g C02=3.88g H20=0.80g. I am oblivious to farther procedures.
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You can determine how much mass of G is present in each of the compounds (You have the molecular weight and the mass percent of G in each compound). If you look at those weights, do you see a trend that you can determine the atomic weight from? What element is this then based on that weight?
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I just skimmed this problem, but think about the following:
The compound contains carbon and hydrogen. When it is burned, only water and CO2 are produced. So this leaves, the elements contained in it, to which?