Answer:
Their answers must be in two decimal places
% error =

x 100%
Experimental: 2.85
Actual (theoretical): 2.70
% error =

x 100% = .055555 x 100% = 5.56%
B is the answer I think better sure
First solve the moles of oxgen present in the compound
mol O = 6.93 g O ( 1 mol O / 16 g O )
mol O = 0.43 mol H
then solve the moles of hydrogen present
mol H = ( 7.36 - 6.93) g H ( 1 mol H / 1 g H)
mol H = 0.43 mol H
so the O and H are in the same mole content so the molecular formula would be OH, but the molar mass will not satisfy. so the answer would be
H2O2