by **celestine** » Wed Sep 14, 2011 1:33 pm

here is your solution and the molecualr formula ..

# moles = mass / molar mass and molar mass of CO2 = 44 g/ mole so

0.659 g of CO2 has 0.659 /44 = 0.0150 moles of CO2

there is 1 mole of C in CO2 and all the C from the compound becomes CO2 so moles of C in the compound = 0.0150 moles

mass of C = 0.0150 x 12 = 0.1797 g

molar mass of H2O = 18 g/ mole

0.089 g of H2O has 0.0892 / 18 = 0.0050 moles of H2O

there are 2 moles of H in H2O so moles of H in the compound = 0.0099 moles

mass of H = 0.0099 x 1.0079 = 0.0100 g

mass of H + C = 0.1897 g

mass of sample = 0.3670 g

mass of Cl by difference = 0.1773 g

moles of Cl = 0.0050 moles

molar ratio of C : H : Cl = 0.0150 : 0.0099 : 0.0050

smallest number 0.0050

divide the ratio by the smallest number we get

molar ratio of C : H : Cl = 3.00 1.98 1

empirical formula is C3H2Cl

this has a formula weight of ( 3x12+2+35.5) or 73.5 g

which is 1/2 the molecular mass

so the molecular formula is 2 x the empirical formula or

C6H4Cl2 dichloro benzene a cancer-causing agent ..