Question

Urgent! Chemistry final exam in 20 minutes please help me!

How do I do something like this. There are 10 grams of Al2O3, how many grams of Al are there?

Answer 1

the alg for it is R U R' U' D F

Answer 2

@steve816
Helpers at OS are not allowed to help with exams, tests, quizzes or any other form of timed evaluation.
By the way, school authorities check websites for evidence of any form of cheating. So it is a good idea to refrain from the practice.

Answer 3

This is not from the exam verbatim. It is a general problem that I am confused about.

Answer 4

I am saying that I will be taking it in 20 min from now.

Answer 5

Ok, can you do the following?
How many grams of Ca are in 100 grams of CaCO3?

Answer 6

yes, I know how to find the molar mass.

Answer 7

Good, what's the approx. molar mass of CaCO3?

Answer 8

and the approximate atomic mass of Ca?

Answer 9

100.087 g/mol

Answer 10

The total is 100 grams, so the mass of Ca would be obtained by solving:
(Mass of Ca)/(mass of CaCO3) = (atomic mass of Ca)/(molar mass of CaCO3)
Is that ok?

Answer 11

oh ok

Answer 12

So proceed the same way with Al2O3, but watch out that it's \(Al_2\), so double the atomic mass of Al in the equation.

Answer 13

Finally, in the future, please post chemistry questions in the chemistry section, and THEN solicit help in other sections with a link to the original question.
Otherwise chemistry helpers don't bother to check the chemistry section, but have to check all over the place.

Answer 14

@mathmate can you please help me?

Answer 15

Please tag me from the question. It's faster for me! lol