Question

5.71 grams of an unknown substance containing carbon, hydrogen and oxygen is burned in excess oxygen to generate 11.78 g of CO2 and 5.32 g of water. Determine the empirical formula for the unknown compound. Which is it? -C3H6O - C3H2O2 -C3H3O -CHO - C2H3O - CH2O

Answer 1

write a balanced equation

substance + oxygen generates carbon dioxide and water
molecular mass of CO2 = 44
moles = mass/molecular mass = 11.78/44 = 0.268
molecular mass of water = 18
moles = 5.32/18 = 0.295
molecular mass of oxygen =32

x + 32 = 44 + 18
x = 30