Question

What is the limiting reactant when 5.6 moles of aluminum react with 6.2 moles of water?

Unbalanced equation: Al + H2O → Al2O3 + H2

Show, or explain, all of your work along with the final answer.

Answer 1

Balanced reaction\[2 Al + 3 H_2O \rightarrow Al_2O_3 + 3 H_2\]How many moles of Al2O3 can 5.6 moles of Al produce? How many moles of Al2O3 can 6.2 moles of H2O produce? The one that produces the smaller amount is the limiting reagent.

Answer 2

The ratio of Al2O3 and Al is 1 to 2
\[5.6 mol of Al \times (1 mol of Al2O3/2 mol of Al) \] which is 2.8 mol of Al2O3

Then the ratio of Al2O3 and H2O is 1 to 3
6.2 mol of H2O x (1 mol of Al2O3/3 mol of H2O) which is 2.067 mol of Al2O3

So the limiting reactant is Al right?

Answer 3

THe limiting reactantn is H2O since it produces less Al2O3.

Answer 4

Oh right. That's what I meant. But I did it right?

Answer 5

Yeah, your work is right, good job =)

Answer 6

Thanks for your help!