Xe(g) + F2(g) ----uv light---> Xe F2(s)

Question

XeF2(g) + 2F2(g) ---catalyst---> XeF6(s)

XeF6(s) + H2O(l) ------> Xe O3(s) + 6HF(g)

Looking at these three reactions respond the following:

a) For each 0.0250 grams of xenon hexaflouride that reacts, what mass of water is requiered?

b)If the three reactions occur in sequence, for each 0.250 grams of xenon that reacts, what is the theoretical yield of hydrogen flouride in grams?

c)If 0.123 moles of xenon flouride reacts with 0.333moles of water, what mass of hydrogen flouride forms?

Answer 1

a)
Convert 0.0250 g XeF6 to moles. moles = grams/molar mass.
Convert moles XeF6 to moles H2O.
moles XeF6 x (1 mole H2O/1 mole XeF6) = mol XeF6 x 1 = ?
Then convert moles H2O to grams. g = moles x molar mass.

b)You CAN work three stoichiometry problems here; i.e., 0.250 g Xe and convert to g XeF2, then use that to convert to g XeF6, then again to convert XeF6 to HF. But you can cut out all of the middle work this way.
Go through the reactions mole for mole like this.
1 mole Xe = 1 mol XeF2 = 1 mol XeF6 = 6 mol HF; therefore, we know 1 mol Xe = 6 mol HF.
mol Xe = 0.250/atomic mass Xe
Convert mol Xe to mol HF like this.
moles Xe x (6 mol HF/1 mol Xe) = mole Xe x (6/1) = ?
Then convert moles HF to grams. g = mols x molar mass. That is the theoretical yield of HF in grams. You an see this is just another stoichiometry problem.

c. This is a limiting reagent problem. I'll leave that for you. Post your work if you get stuck.