Transcript Slide 1

THE
AP Chemistry
Exam
Two Sections
1. Multiple Choice
2. Free Response
185 minutes total
Section I
75 Multiple Choice Questions
(50% of score)
Periodic Table only
NO calculator
90 minutes
Grading
1
MC score  # right - # wrong
4
Section II:
Free Response
(50% of score)
Periodic Table
Equations Sheet
Reduction Potential Table
Section II:
Free Response
Part A
Quantitative Section
CAN USE calculator
55 minutes
A graphing or scientific
calculator is permitted.
Excludes
Power Books
PDA
QWERTY keypad
w/paper tapes
models that talk
require outlet
cell phone
#1
Quantitative Problem
(Equilibrium)
[10% of score]
#2 & #3
Quantitative Problems
(any topic)
[may be lab]
[each 10% of score]
Section II
Free Response
Part B
Equations & Short Answer
NO calculator
40 minutes
#4
Three (3) Equations
Balance
Answer short question
(answer in box)
[5% of score]
Question 4—Reactions
3 reactions
1 point for reactants
2 points for products
1 point for balance
1 point for question
 For
each of the following three
reactions, in part (i) write a BALANCED
equation and in part (ii) answer the
question about the reaction.
Coefficients should be in terms of
lowest whole numbers. Assume that
solutions are aqueous unless otherwise indicated. Represent substances
in solutions as ions if the substances
are extensively ionized. Omit formulas
for any ions or molecules that are
unchanged by the reaction.
Examples




Example: A strip of magnesium is
added to a solution of silver nitrate
Mg + 2 Ag +  Mg 2+ + 2 Ag
Which substance is oxidized in the
reaction?
Magnesium metal (Mg)
4. Solid potassium chlorate is strongly
heated resulting in a change in the
oxidation numbers of both chlorine and
oxygen.
 (i)
2 KClO3  2 KCl + 3 O2
(ii) What is the oxidation number of
chlorine before and after the
reaction?
 Chlorine
has an oxidation number
of +5 in KClO3 and -1 in KCl
4. A solution of ethanoic (acetic) acid is
added to a solution of barium
hydroxide.

i. HC2H3O2 + OH-  H2O + C2H3O2-
(ii) Is a solution composed of
stoichiometric amounts of ethanoic acid
and barium hydroxide acidic, basic, or
neutral? Why
 Basic, because of the hydrolysis of the
C2H3O2- .
4. Zinc metal is placed in a solution of
copper(II) sulfate.
(i) Zn + Cu2+  Zn2+ + Cu
(ii) Describe the change in color of the
solution that occurs as the reaction
proceeds.
 The blue color of the solution due to
the presence of the hydrated
copper(II) ion fades as the copper(II)
ion reacts and the colorless hydrated
zinc(II) ion forms.
4. Hexane is combusted in air.
2
C6H14 + 19 O2 12 CO2 + 14 H2O
(ii) When one molecule of hexane is
completely combusted, how many
molecules of products are formed?
 1 molecule of hexane produces 13
molecules of products
#5 & #6
Short Answer
(any topic)
[may be lab]
[each 7.5% of score]
Grading protocol
established & points
awarded for each part.
Conditional grading is
in effect.
Grading
•Quantitative Problems
& Short Answer
•(each 8-10 pts)
•Equations (15 pts)
•Standardized