Phosphous burning in air

[Guest adeyave]

I need help with how to calculate the empirical formula and molecular formula for the reaction between phosphorus burning in air.

I have already have the information that Phosphorus burns in air to form diphosphorus pentoxide(flowers of Phosphorus), P2o5. I need the formula for the production of a waxy crystalline solid compound (a different form of phosphorus oxide )that is produced as the phosphorus continues to burn in a limited supply of air.

 

I believe that the solid is phosphorus oxide and am being asked to work out the empirical formula on the basis that it is 56.4% phosporus and 43.6% oxygen also taking into account the relative atomic masses of the two elements .

I think the answer is P2 o3 for the empirical formula and P4O10 for the molecular formula but need to know how to work it through and whether I am right.

[budullewraagh]

atomic mass of P=30.973761

atomic mass of O=15.9994

 

let me check your work...

molecular mass P2O3=110

48/110=.43636363636...

62/110=.56363636363...

 

let's see what cambridge university, england has to say about P4O10...

http://chemfinder.cambridgesoft.com/ChemIndex/ChemIndex/ChemIndex_action.asp?formgroup=base_form_group&dbname=ChemIndex&dataaction=Get_structure&Table=MolTable&Field=MOL_ID&DisplayType=sizedgif&width=225&height=200&StrucID=2373

it's hygroscopic, decomposes in H2O, has a vapor density of 4.9, a melting point of 340 degrees celcius, has a density of 2.39g/mL and a molecular mass of 283.88904.

 

quite the interesting compound.