Transcript Chemical Equations (Chapter 11) & Stoichiometry (Chapter 12)

Look over objectives and try those types of
problems on past worksheets and quizzes,
especially if you know you are weak on it
• Come in for help before the test for extra help or
to retake quizzes!
• These are the “clicker” questions from this unit
– Ans: (2) B (3) B (4) A (5) C (6) A (7) D (8) D (9) A (10)
B (11) B (12) D (13) C (14) B (15) B (16) D (17) D (18)
D (19) D (20) B (21) D (22) C (23) C (24) D
– Notably missing from these are questions about
identifying types of reactions and why we balance
equations and how you know an equation is balanced
What are the products in the
following chemical equation:
Zn + CuSO4  ZnSO4 + Cu
A.) zinc and copper
B.) zinc sulfate and copper
C.) zinc and copper (II) sulfate
D.) only zinc
Given the incomplete equation:
4Fe + 3O2  2X
Which compound is represented by X?
A.) FeO
B.) Fe2O3
C.) Fe3O2
D.) Fe3O4
CaSO4 + AlCl3  Al2(SO4)3 + CaCl2
What is the coefficient of Al2(SO4)3 when the
equation is completely balanced using the smallest
whole-number coefficients?
A.) 1
B.) 2
C.) 3
D.) 4
Given the incomplete equation:
2N2O5(g) 
Which set of products completes and
balances the incomplete equation?
A.) 2N2(g) + 3H2(g)
B.) 2N2(g) + 2O2(g)
C.) 4NO2(g) + O2(g)
D.) 4NO(g) + 5O2(g)
Given the unbalanced equation:
Al + O2  Al2O3
When this equation is completely
balanced using smallest whole
numbers, what is the sum of the
coefficients?
A.) 9
B.) 7
C.) 5
D.) 4
If you rewrite the following word equation as a
balanced chemical equation, what will the
coefficient and symbol for fluorine be?
nitrogen trifluoride  nitrogen + fluorine
A.) 6F2
B.) F3
C.) 6F
D.) 3F2
Complete a balanced equation for the following
reaction.
Ag(s) + KNO3(aq) 
A.) AgNO3 + K
B.) AgK + NO3
C.) AgKNO3
D.) No reaction
A double-replacement reaction takes place
when aqueous Na2CO3 reacts with aqueous
Sn(NO3)2. You would expect one of the
products of this reaction to be ________.
A.) NaNO3
B.) NaSn
C.) Sn(CO3)2
D.) CNO3
What is the balanced chemical
equation for the reaction that takes
place between bromine and sodium
iodide?
A.) Br2 + NaI  NaBr2 + I
B.) Br2 + 2NaI  2NaBr + I2
C.) Br + NaI2  NaBrI2
D.) Br + NaI2  NaBr + I2
Given the balanced equation representing a reaction:
F2(g) + H2(g)  2HF(g)
What is the mole ratio of H2(g) to HF(g) in
this reaction?
A.) 1:1
B.) 1:2
C.) 2:1
D.) 2:3
Given the reaction:
6 CO2 + 6 H2O  C6H12O6 + 6 O2
What is the total number of moles of water
needed to make 2.5 moles of C6H12O6?
A.) 2.5
B.) 6.0
C.) 12
D.) 15
Given the balanced equation:
2 C4H10 + 13 O2  8 CO2 + 10 H2O
What is the total number of moles of O2 that
must react completely with 5.00 moles of
C4H10?
A.) 10.0
B.) 20.0
C.) 26.5
D.) 32.5
2Pb(NO3)2(s)  2PbO(s) + 4NO2(g) + O2(g)
How many grams of oxygen are produced
when 11.5 grams of NO2 is formed?
A.) 1.00 g
B.) 2.00 g
C.) 2.88 g
D.) 32.0 g
4Fe(s) + 3O2(g) 2Fe2O3(s)
How many grams of Fe2O3 are formed
when 16.7 grams of Fe reacts completely
with oxygen?
A.) 12.0 g
B.) 23.9 g
C.) 47.8 g
D.) 95.6 g
H3PO4 + 3 NaOH Na3PO4 + 3 H2O
What mass of Na3PO4 can be prepared by
the reaction of 4.90 g of H3PO4 with an
excess of NaOH?
A.) 7.12
B.) 7.44
C.) 7.82
D.) 8.20
E.) 8.95
Ca + F2  CaF2
What is the limiting reagent and what
quantity of CaF2 results from the reaction of
3.00 g of calcium and 2.00 g of fluorine?
A.) Ca, 4.78
B.) F2, 4.78
C.) Ca, 4.11
D.) F2, 4.11
E.) Ca, 3.22
Once the limiting reactant is all
used up in a reaction, the left-over
reactant is known as
A.) the product
B.) the limited reactant
C.) the limiting reactant
D.) the excess reactant
The reactant you run out of first is
known as
A.) the running reactant
B.) the excess reactant
C.) the absent reactant
D.) the limiting reactant
When we use a balanced equation
to predict the number of grams of a
product in a reaction, we get the
A.) product yield
B.) theoretical yield
C.) percent yield
D.) actual yield
In an experiment, students determined
the theoretical yield to be 20 grams.
Their actual yield was 15 grams. What
was their percent yield?
A.) 133%
B.) 1.33%
C.) 0.75%
D.) 75%
In an experiment, students determined
the theoretical yield to be 12 grams.
Their percent yield was 90 percent.
What was their actual yield?
A.) 13.3 g
B.) 5.3 g
C.) 10.8 g
D.) 7.5 g
Cu + 2AgNO3  Cu(NO3)2 + 2Ag
12.7 grams of Copper produces 38.1 grams
of Silver in a laboratory. What is the
percent yield of this reaction?
A.) 56.7 %
B.) 77.3 %
C.) 88.9 %
D.) 176 %
4 NH3 + 5 O2  4 NO + 6 H2O
The reaction of 0.68 g of NH3 with excess
O2 according to the following reaction yields
0.98 g of NO. What is the percent yield?
A.) 72%
B.) 74%
C.) 78%
D.) 82%
E.) 86%