What's the percent composition of 2H2+O2--> 2H2O?
For the percent composition would you divide h2 /h20 and o2/h2o? For 2H2O would the lewis structure look any different if it was just an H2O lewis structure, if so how would it look?
H -- O -- H (bent, Oxygen has 2 lone pairs)
Hydrogen percent composition = [ 2 * (Hydrogen mass) ] / [Total mass of H2O]
Oxygen percent composition = [Oxygen mass] / [Total mass of H2O]