How to find the empirical formula?

Question

Hi,

What would be the empirical formula for phosphorus selenide?

Answer 1

do you have any data?

find moles:

take the (grams of Phosphorus) / (30.97 g/mol) =  ____moles P

take the (grams of Selenium) / (78.96 g/mol) =  ____moles Se

ratio the moles to get whole  numbers:

____moles P / (the smaller of the two moles) = moles P

____moles Se / (the smaller of the two moles) = moles Se

if one the moles of p to Se come out to be:

P Se0.75 , ...four times  the ratio to P4Se3

P Se2.5 , ...double the ratio to get P2O5

P Se 1.25 , ... four times the ratio to get P4Se5

P Se1.75 , ... four times the ratio to get P4Se7

these are some tof the posibilities for empirical formulas:

P Se

P4Se3

P2Se5

P4S5

P4S7

e-mail me if you have data , or questions