[unleash10]

Problem: I have little idea how to do this problem.

1.84 x 10^-4 mol of Xe and 5.00 x 10^-4 F2 were allowed to react to form a mixture of XeF4 and XeF6. 9.00 x 10^-6 mol of unreacted Xe was present after the complete of the reaction. What is the mass % of XeF4 in the mixture?

I understand a lot of the harder stoichiometry problems require algebra and working backwards.

Can someone explain to me what happens to the mol of the reactants(theoretically) when it is reacted? Does 1.75 x 10^-4 mol Xe from the reactant form both 1.75 x 10^-4 mol Xe in XeF4 and XeF6 or does the combination of mols of Xe in XeF4 and XeF6 equal
1.75 x 10^-4?

What do i need to understand in order to do this problem? How do you approach more difficult stoichiometry problems?

[Mitch]

Read Signature.

[AWK]

hint
always start writing down a balanced reaction

[unleash10]

Im stuck  .

[Borek]

Does 1.75 x 10^-4 mol Xe from the reactant form both 1.75 x 10^-4 mol Xe in XeF4 and XeF6

Do you mean there are 1.75*10^-4 XeF₄ and 1.75*10^-4 XeF₆? This is obviously wrong.

or does the combination of mols of Xe in XeF4 and XeF6 equal 1.75 x 10^-4?

Correct.

Nothe that there are two different reaction equations in this case.

[unleash10]

question: how do you know if there are two seperate reactions?

[Borek]

You have two separate products. In some cases it may mean there is a more complicated reaction in which both products are created, but then their ratio will be stoichiometric.

[AWK]

Xe + 2F2 = XeF4
x
Xe + 3F2 = XeF6
y

x+y = ?
2x+3y = ?

When you find x and y then you can calculate mass of XeF4.

[unleash10]

Thanks guys I figured it out and got 12.4%.