Question

Find the empirical formula: 0.31g of phosphorus reacts to form 0.71g of phosphorus oxide. The oxide has a relative molecular mass of 284.

Answer 1

4P+5O2-->P4O10
Use the equation Number of moles=Mass(g)/Molar Mass(g/mol)
0.31/30.9=0.0100
0.71/284=0.0025
Divide by the smallest figure
0.0100/0.0025=4 moles of Phosphurus
0.0100/0.0100=1 moles of P4O10