What quantities are
conserved in
chemical reactions?
grams and atoms
What quantities are not conserved
in chemical reactions?
liters and moles
When calculating percent yield, actual
yield and theoretical yield are always
____________ of the same
____________.
grams, product
How many moles of Ca(OH)2
are needed to react completely with
2.35 moles of Al2(SO4)3 according to
the following balanced chemical
reaction?
Al2(SO4)3 + 3Ca(OH)2  2Al(OH)3 + 3CaSO4
7.05 moles Ca(OH)2
Using the following balanced
equation, calculate the number of
grams of water formed when 0.75
moles of B(OH)3 are used in the
reaction.
3 H2SO4 + 2 B(OH)3  B2(SO4)3 + 6H2O
40.54 g H2O
How many moles of MgO
form from the reaction
below if enough reactants
are used to form 15.98 g
of Fe?
3 Mg + Fe2O3  2 Fe + 3 MgO
0.43 mol MgO
Using the following equation:
Pb(SO4)2 + 4 LiNO3  Pb(NO3)4 + 2 Li2SO4
How many grams of lithium nitrate
will be needed to make 250 grams
of lithium sulfate, assuming that
you have an adequate amount of
lead (IV) sulfate to do the reaction?
313.58 g LiNO3
How many liters of NH3
at STP form when 15.23
g of ammonium carbonate,
(NH4)2CO3, decompose
according the following
balanced equation?
(NH4)2CO3  H2O + 2NH3 + CO2
7.10 L NH3
Calcium carbonate decomposes to
form carbon dioxide and calcium
oxide:
CaCO3 (s)  CO2(g) + CaO(s)
How many grams of calcium
carbonate will I need to form 3.45
liters of carbon dioxide at STP?
15.42 g
Ethylene burns in oxygen to form
carbon dioxide and water vapor:
C2H4(g) + 3 O2(g)  2 CO2(g) + 2 H2O(g)
How many liters of water vapor can be
formed if 1.25 liters of ethylene are
consumed in this reaction? Assume all
substances are at the same
temperature and pressure.
2.50 L H2O
Calculate the following:
a) Which of the reagents is the limiting reagent?
b) How many grams of each product are
formed?
c) How many grams of excess reactant remain?
3 NH4NO3 + Na3PO4  (NH4)3PO4 + 3 NaNO3
Assume we started with 30 grams of ammonium
nitrate and 50 grams of sodium phosphate.
a) ammonium nitrate
b) 18.6 grams of ammonium phosphate,
31.9 grams of sodium nitrate
c) 29.5 grams of sodium phosphate
If the percent yield of the
following equation is 55%, how
many grams of H2SO4 are
produced when 44.8 L of SO3
are combined with excess
water? Assume the reaction
occurs at STP.
SO3(g) + H2O(l)→H2SO4(aq)
107.89 g H2SO4
A 2.00 g sample of ammonia is
mixed with 4.00 g of
oxygen. Which is the limiting
reactant and how many grams of
excess reactant remains after the
reaction has stopped?
4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g)
oxygen, 0.30 g NH3
90.0 g of FeCl3 reacts with 52.0 g
of H2S, according to the following
balanced equation:
2FeCl3 + 3H2S Fe2S3 + 6HCl
What is the limiting
reactant? What is the mass of HCl
produced? What mass of excess
reactant remains after the
reaction?
FeCl3, 60.8 g HCl, 23.6 g H2S
If 12.0 mL of 1.34 M NaOH is required
to neutralize 25.00 mL of a sulfuric
acid, H2SO4, solution, what is the
molarity of the sulfuric acid?
The balanced titration reaction is
H2SO4(aq) + 2NaOH(aq) Na2SO4(aq) + 2HOH(l).
0.322 M H2SO4
What volume (in mL) of 0.075 M HCl is
required to neutralize 100 mL of 0.01 M
Ca(OH)2 solution? The balanced titration
reaction is
2HCl + Ca(OH)2  2H2O + CaCl2.
26.7 mL HCl