Qhow many moles of water are formed from 100g H2 and 100g O2 asssuming the reaction goes to completion?
1) write out formula: H2+.5O2-> H2O
2) find limiting reactant- its oxygen bc it has a heavier molar mass compared to hydrogen therefore there are less moles of O2 in 100g than moles of H2. dont bother doing the calculation: save time
3) set up dimensional anaylsis:
100 g O2 x (1 mol O2/ 32g O2) x ( 1 mol H2O/ .5 mol O2) = 100/(32x.5) or 2(100/32) which is choice C