Question

When 0.422g of phosphorus is burned 0.967g of a white oxide is obtained. Determine the empirical formula of the oxide

Answer 1

now what's that we gonna use the combustion analysis here too @Photon336 Sir???

Answer 2

@Shalante this is your type of problem.

Answer 3

i'm not sure myself @Shikamaru11 thoughts?

Answer 4

Combustion is when u burn it in air soo we have to write the balanced equation for the reaction between phosphorus and O2

Answer 5

Sir will be the equation is something like that??????????
\[P+ZnO \rightarrow ????\] hope i could think far

Answer 6

Wait I dnt think we need to go for the equation. We can just assume that all of the phosphorus is now in the oxide.

Answer 7

\(\color{#0cbb34}{\text{Originally Posted by}}\) @Rushwr
Combustion is when u burn it in air soo we have to write the balanced equation for the reaction between phosphorus and O2
\(\color{#0cbb34}{\text{End of Quote}}\)

yeah, was thinking that too, BTW where did the zinc come from?

Answer 8

Considering phosphorus as the limiting agent

Answer 9

oh I got that in a second shot I think it mentioned white oxide but it's the obtant so my hypothesis failed :P

Answer 10

hey my guess of PO4 lolxxxx :P

Answer 11

we only need to find the empirical formula of the oxide right?
So what if we consider that all of the phosphorus present are in the oxide now ? So the rest of the mass that is from 0.967 is oxygen
SO the mass of oxygen in the oxide = 0.967 - 0.422 = 0.545g
We can find the no. of moles of each separately
Moles = mass/ molar mass
moles of P = 0.422/ 31 = 0.014 moles
Moles of Oxygen = 0.545/16 = 0.034 moles

Now divide each by the smallest no. of moles

Now the ratio between P: O is 1:2.5
But we can't keep the ration in decimal numbers so to make it a whole number we multiply it by 2 so the new ratio would be 2:5
So the empirical formula would be P2O5