Empirical Formula qst

[lacoste]

How do we know what factor to multiply the emprical numbers to so that it is very close to a whole number?

Eg. C   :   H

     1    :  2.3

>C₇H₁₆


(i figured out that it was 7 after a long waste of time with the calc, i thought that maybe there is a way that is not trial and error?)


thanks, mates

[dekoyl]

I thought it might be 3?

C : H
1 : 2.3
3 : 6.9



As for how I did it (if it's right).. I can't give you a direct answer, sorry (because I don't have one).

[lacoste]

The solution said it was C₇H₁₆.


But your answer seems more accurate because its the lowest figure and both are out by 0.1.

hmmm, but does anyone know a way to get the 'factor' to be multiplied with ease?

[lacoste]

As for how I did it (if it's right).. I can't give you a direct answer, sorry (because I don't have one).

trial and error?

[Edmund]

I would say C3H7

But does the question ask about having alkane or alkene, that sort of stuff?

[lacoste]

I would say C3H7

But does the question ask about having alkane or alkene, that sort of stuff?

Nope, I don't know why they got that. If it was alkane or alkene what would it be?

[/0]

is neither alkane nor alkene. I don't think it can exist.

follows the rule for alkanes.

[lacoste]

Ahh thanks, i remember that now. thanks.

[lacoste]

Another q.

If 3.72 g of element X reacts with exactly 4.80 g of oxygen to form a compound whose molecular formula is shown, from other experiments, to be X₄O₁₀, what is the relative atomic mass of X?

I don't get the steps in the solution.

[Mao]

[lacoste]

Don't get that? O__O

Why is the 10 there for, what does it mean? ..

And also, I don't get the 2 x n(O)?

[Mao]

oops, typo. I meant 2 x n(O₂)

the number of moles of oxygen consumed has a ratio to the number of moles of X by the chemical formula X4O10. that is, for every 10 oxygen atoms, , there are 4 X,