# chemistry

posted by on .

Suppose 87.9 grams of FeCl3 reacts with excess aluminum metal to produce 22.3 grams of Fe. What would be the % yield?

FeCl3 + Al --> AlCl3 + Fe

• chemistry - ,

Why must the water levels be equal in a tube before measuring the volume of gas?

• To Amy---chemistry - ,

FeCl3 + Al --> AlCl3 + Fe

mols FeCl3 = grams/molar mass.
mols Fe = mols FeCl3 (look at the coefficients in the equation).
Convert mols FeCl3 to g. g = mols x molar mass. This is the theoretical yield.
Then %yield = (actual yield/theoret yield)*100 = ?

• To Sarah---chemistry - ,

You're questions often get overlooked when you double post like this. It is much better if you go to the top of the page and click on Post a New Question.

You want the water levels inside the tube and outside the tube to be the same because you want the pressure inside the tube to be the same as that outside the tube. You can't measure the pressure inside the tube (but that's what you want) but you CAN measure the pressure outside the tube (that's atmospheric pressure) and that's easy to measure.