[hwylee]

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.

[macman104]

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?

[I.B.D.]

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?