[alwaysanewb]

9.73g of lead (IV) chloride contains enough CL^- ions to make___g of magnesium chloride.
Can someone walk me through this? I've been away from chem for awhile.

[UG]

Calculate the number of moles of PbCl₄. This is done by dividing the mass by the molar mass.
One mole of PbCl₄ has 4 moles of chloride ions, so you can work out how many moles of chloride ions there are. Every two chloride ions will combine with one magnesium ion to form MgCl₂. The mass of MgCl₂ is calculated by multiplying the number of moles of magnesium ions needed (since the mole ratio MgCl₂:Mg is 1:1 whereas MgCl₂:Cl^- is 1:2) to react with the chloride ions by the molar mass of magnesium chloride.

[alwaysanewb]

Okay,
Calculated that there are 0.0278 moles of PbCl₄ in 9.73 grams of PbCl₄.
What next?

[Borek]

What next?

Most likely you should read next phrase of the UG post.

[alwaysanewb]

What next?

Most likely you should read next phrase of the UG post.

I wish I could relate to your sarcasm. I'm sourly unsure of how to do the next step.
If you can help then post.  Please don't waste my time.

[alwaysanewb]

Okay,
Calculated that there are 0.0278 moles of PbCl₄ in 9.73 grams of PbCl4.
Then,
Found percent composition of Cl in PbCl₄ which is 40.6%.
Took 40.6% of 0.0278g which is 0.0113g.
So I assume that 0.0113g is the amount of Cl moles in 0.0278 moles of PbCl₄

[sjb]

Okay,
Calculated that there are 0.0278 moles of PbCl₄ in 9.73 grams of PbCl4.
Then,
Found percent composition of Cl in PbCl₄ which is 40.6%.

So far, so good

Took 40.6% of 0.0278g which is 0.0113g.
So I assume that 0.0113g is the amount of Cl moles in 0.0278 moles of PbCl₄

Where has the 0.0278g come from?

[alwaysanewb]

the 0.0278g came from 9.73g / 349.0230

moles= mass/molar mass

[Borek]

Seems like you have no idea what mole is

You are calculating number of moles and write that result is a mass. It is not.

the 0.0278g came from 9.73g / 349.0230

moles= mass/molar mass

It is not 9.73g/349.023 - you should list all units. You would get 9.73g/349.023(g/mol) and the result would be 0.0278 mole, not 0.278 g.

Mole is just an overgown dozen - instead of having 12 elements like dozen has, mole has 6.02*10²³ elements.

If there are 0.0278 moles of PbCl₄, how many atoms of Pb? How many atoms of Cl? Knowing how many atoms of Cl in the sample, can you calculate number of moles of chlorine?

[alwaysanewb]

I found that there are 0.0028 moles of Cl in 9.73g of PbCl₄.
Is this correct? 
I calculated this using algebraic ratio and %

[Borek]

No, it is wrong. You don't need % to calculate it.

How many PbCl₄ molecules in one mole?

How many chlorine atoms in PbCl₄ molecule?

How many Cl atoms in one mole of PbCl₄?

How many moles of Cl in one mole of PbCl₄?