# chemistry quick help!

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In the balanced double replacement reaction of calcium chloride CaCl2 and aluminum sulfate Al2(SO4)3, how many grams of calcium sulfate can be produced if you start the reaction with 4.19 grams of calcium chloride and the reaction goes to completion?

• chemistry quick help! - ,

6CaCl2 + 2Al2(SO4)3 = 6CaSO4 + 4AlCl3

So, now you know that each mole of CaCl2 produces one mole of CaSO4

How many moles in 4.19g of CaCl2?
How many g in that much CaSO4?

• chemistry quick help! - ,

6 mols?
so 4.19x6?

• chemistry quick help! - ,

1 mole of CaCl2 is about 111 g
(Ca = 40, Cl = 35.5)
So, 4.19g is not 6 moles!

• chemistry quick help! - ,

so 4.19/111?

• chemistry quick help! - ,

that's better

• chemistry quick help! - ,

that answer is also wrong though

what am I missing?

• chemistry quick help! - ,

Looking at my equation, I see i could have factored out a 2:

3CaCl2 + Al2(SO4)3 = 3CaSO4 + 2AlCl3

that does not affect the relative amounts, however.

4.19/111 = .0377 moles CaCl2
.0377 moles CaSO4 = .0377*136 = 5.13g
Did you forget to calculate the grams, as they asked? You need the relative quantities in moles, but you have to convert grams of input to moles, then back to grams of output.