STOICHIOMETRY & PERCENT YIELD CLASSWORK

1.)  Solid iron (III) oxide reacts with hydrogen gas according to the following equation:

___ Fe2O3  +  ___ H2  à  ___ Fe  +  ___ H2O

(A) How many moles of iron are produced when 450 grams of iron (III) oxide are reacted?

(B) How many grams of water will be produced when 0.0155 moles of hydrogen gas react
completely with iron (III) oxide?

2.)  Lithium nitride reacts with water to produce ammonia and lithium hydroxide according to the
following equation:       ___ Li3N  +  ___ H2O
à  ___ NH3  +  ___LiOH
(A) Determine the mass (in grams) of lithium hydroxide produced when 10.87 grams of lithium
nitride reacts with excess water.

(B) The reaction in part (A) was performed by a group of students.  If the group recovered 20.41
grams of lithium hydroxide, what was the lab group’s percent yield?

3.)  How many molecules of methane (CH4) can be produced by reacting 37.95 grams of aluminum
carbide with excess HCl?

___ Al4C3  +  ___ HCl  à  ___ CH4  +  ___ AlCl3

4.)  How many moles of water are needed to react with 0.23 moles of chlorine according to the
following equation?

___ Na2S2O3  +  ___ Cl2  +   5  H2O  à  ___ NaHSO4  +  ___HCl

5.)  What mass (in grams) of H2SO4 is required to react completely with excess NaHCO3 in order to
produce 6.75 x 1023 molecules of CO2?

___ NaHCO3  +  ___ H2SO4  à  ___ Na2SO4  +  ___ H2O  + ___ CO2