Textbook question F.13

[305607822]

The question is: In an experiment, 4.14 g of phosphorus combined with chlorine to produce 27.8 g of a white solid compound. (a) What is the empirical formula of the compound? (b) Assuming that the empirical and molecular formulas of the compound are the same, what is its name?

So I found mols of phosphorus but I don't know where to go from there. Can I just assume that P + Cl = PCl ? I feel like I'm missing some information, so if anyone can help that'd be awesome.

[Jason Ho 2L]

So we know from the question that there are 4.14 g of phosphorous. We also know that there is 27.8 g of a substance made up of phosphorous and chlorine. Take 27.8 g - 4.14 g to get 23.66 g Cl.

Knowing both the grams of phosphorous and chlorine, convert both of them to moles and divide by the one with the least amount of moles. In this case, that would be phosphorous. You should end up getting PCl5.

[Olivia Peony Dis 2A]

Hi! So we can start with the equation
Cl in nature exists as Cl2, like H2 and O2.
Hence in the equation we can start with P+Cl2-->PnCl2n
with n being a whole number
next, we need to find exactly what mass of P and Cl2 there is, and since we know P and the total mass of product (27.80 grams) we can find the mass for Cl2. Then we can calculate % mass of each P and Cl2 using massP/mass total x 100. And the same for Cl2. Then just use the steps of dividing with Atomic mass and finding the ratio of the atoms.

Hope this helps :)

Olivia Peony Dis 2E

[alexjung1A]

The question is: In an experiment, 4.14 g of phosphorus combined with chlorine to produce 27.8 g of a white solid compound. (a) What is the empirical formula of the compound? (b) Assuming that the empirical and molecular formulas of the compound are the same, what is its name?

So I found mols of phosphorus but I don't know where to go from there. Can I just assume that P + Cl = PCl ? I feel like I'm missing some information, so if anyone can help that'd be awesome.

Yes, you can assume that the grams did not change because the moles of stuff did not change either (law of conservation of mass and there's no excess product other than the resulting compound).