question regarding empirical formula and molecular formula(finding 2 variables)A Lvel


by mutineer123
Tags: compound, empirical formula, molecular formula, relative atomic mass
mutineer123
mutineer123 is offline
#1
Mar5-12, 07:56 PM
P: 93
1. The problem statement, all variables and given/known data

http://www.xtremepapers.com/CIE/Inte..._s11_qp_12.pdf

question 10




2. Relevant equations




3. The attempt at a solution
The way I am doing it, is to get two equations in terms of x and y and then equate them. For the first equation I used the fact that all of the element's individual atomic masses will add up to 571.5. So i got 27x + 28.1y = 172
My problem now is how to get the second equation? I think it has something to do with the empirical formula, but I can't figure it out. Help!
Phys.Org News Partner Science news on Phys.org
Simplicity is key to co-operative robots
Chemical vapor deposition used to grow atomic layer materials on top of each other
Earliest ancestor of land herbivores discovered
sjb-2812
sjb-2812 is offline
#2
Mar6-12, 07:20 AM
P: 418
If you remove the Al and Si from the formula, what is the charge on the resulting ion?
Borek
Borek is offline
#3
Mar6-12, 07:34 AM
Admin
Borek's Avatar
P: 22,665
What is 14.04% of 571.5?

mutineer123
mutineer123 is offline
#4
Mar6-12, 10:43 PM
P: 93

question regarding empirical formula and molecular formula(finding 2 variables)A Lvel


Quote Quote by Borek View Post
What is 14.04% of 571.5?
I think I got it, thanks to you. So for x we find 14.17% of 571.5. That answer we divide by 27, (because we know that the mole of aluminium is 1), and the x i got is 2.999(pretty close to one of the options). Same for y. Thanks!


Register to reply

Related Discussions
empirical and molecular formula Chemistry 1
What is the Empirical and Molecular Formula of Caffeine? Biology, Chemistry & Other Homework 0
Finding Empirical Formula Question Biology, Chemistry & Other Homework 1
Molecular Formuals from Empirical Formula Help Please! Biology, Chemistry & Other Homework 2
from empirical formula to molecular formula (need help) Biology, Chemistry & Other Homework 6