Sample Problems Of Formula Mass

1) Calculate the molar mass of any given compound. (example problems on pg 238-239 ) A) H2SO4 molar mass of H________ x 2 = _______ molar mass of S________ x 1 = _______ molar mass of O _______ x 4 = _______ SUM = ______________ B) C3H8 2) Use molar mass to convert between mass in grams and amount in moles of a chemical compound and number of molecules. (example problems on pg 240-42) C) Find the mass in grams of 5 moles of NaOH. molar mass of Na________ molar mass of O________ molar mass of H _______ SUM = ______________ g/mol X 5 moles = _______________ D) Find the number of moles of methanol (CH3OH) in 96 grams of methanol.

E) Find the number of molecules in 220 grams of dry ice (CO2). i) Calculate molar mass of CO2 (problems A and B)

ii) Convert 220 grams to # of moles

iii) Convert number of moles to number of molecules

F) Find the mass in grams of 1.20*1024 PO33- ions.

Easy Convert from moles to gram 1) 5.00 moles of carbon dioxide (CO2) 2) 2.50 moles of barium chloride (BaCl2) 3) 7.50 mole xenon tetrafloride (XeF4) Convert from # of molecules to grams 4) 6.022*1023 molecules of methane (CH4) 5) 1.51*1023 molecules of sulfur dioxide (SO2) 6) 1.20*1025 molecules of butane (C3H8)

Tricky Convert from moles to gram 1) 15.0 moles of aluminum oxide 2) 4.23 moles of iron (II) chloride 3) 3.250 mole Magnesium perchlorate Convert from # of molecules to grams 4) 6.022*1023 molecules of sulfuric acid 5) 1.54*1026 molecules of tin (IV) nitride 6) 6.20*1025 molecules of dinitrogen tetroxide