Composition of metal alloy

  • Thread starter johndoe
  • Start date
  • #1
41
0
A metal alloy consists of magnesium and aluminum.When a 1.00g sample of the alloy is reacted with excess HCl, 0.0989g of hydrogen gas forms. Calculate the percent composition of the alloy.

Ok I got the following balanced equations :

Mg + 2HCl -> MgCl2 + H2
2Al + 6Hcl -> 2AlCl3 + 3H2

Can I say 1 mole of Mg reacts with 1 Mole of H2, with H2 being 1/4 of 0.0989g and
2 moles of Al reacts with 3 moles of H2, with H2 being 3/4 of 0.0989g?
 

Answers and Replies

  • #2
Borek
Mentor
28,705
3,195
No, you can't. That will happen only if you will know you have mixture of 1 mole of Mg and 2 moles of Al, you don't know neithe rhow many moles of both nor in waht ratio you have.

Write two equations - one for sum of masses of metals, one for sum of numbers of moles of metals. The latter will use moles of hydrogen produced and stoichiometry of the reactions provided.
 

Related Threads on Composition of metal alloy

  • Last Post
Replies
4
Views
6K
Replies
1
Views
18K
  • Last Post
Replies
1
Views
2K
Replies
10
Views
5K
  • Last Post
Replies
5
Views
4K
Replies
1
Views
9K
Replies
0
Views
3K
  • Last Post
Replies
11
Views
4K
  • Last Post
Replies
1
Views
11K
  • Last Post
Replies
3
Views
1K
Top