Passport to Science Exploration: Chemistry Connections
Sample Questions
—Students may use a periodic table for all questions below—
(1) Zinc(II) acetate, Zn(C2H3O2)2, is a chemical compound that is often used to treat the
common cold. What is the chemical formula of an acetate ion?
A.
B.
C.
D.
C2H3O2
(C2H3O2)2
C2H3O2−
C2H3O22−
(2) Cl2O7 is one of several oxides formed by chlorine and oxygen. What is the IUPAC name
for Cl2O7?
A.
B.
C.
D.
Chlorate
Chlorine(I) oxide
Dichlorine septoxide
Dichlorine heptoxide
(3) Based on the portion of the periodic table shown below, which of the following
elements has the largest atomic radius?
A.
B.
C.
D.
Argon
Carbon
Neon
Silicon
(4) When continually heated in a sealed container, ammonium chloride decomposes into
ammonia and hydrogen chloride as shown in the reaction below. Which of the following
must be true of this reaction?
NH4Cl(s) ⇌ NH3(g) + HCl(g)
A. The reaction can occur without heat if a catalyst is present
B. The forward reaction has a lower activation energy than the reverse
reaction
C. The transition state of the forward reaction is less stable than the
transition state of the reverse reaction
D. ∆E of the forward reaction equals negative ∆E of the reverse reaction
(5) Hydroxylamine, shown below, is used as a neutralizer in photograph developing
solutions. What is the total number of electrons shared between atoms in one molecule
of hydroxylamine?
A.
B.
C.
D.
4
8
10
14
(6) Nitric oxide in the human body helps cells respond to their environment. The formation
of nitric oxide, shown below, requires a greater amount of energy to break the N2 and
O2 bonds than it releases when the NO bonds are formed. Which of the following does
not describe the formation of nitric oxide?
N2(g) + O2(g)  2NO(g)
A.
B.
C.
D.
A synthesis reaction
An exothermic reaction
An oxidation reaction
A reduction reaction
2016-2017 Sample Questions – Chemistry Connections
Copyright 2017 Chemical Educational Foundation®
(7) Based on the pH values in the table below, which list of solutions is ordered from
highest hydroxide ion concentration to lowest hydroxide ion concentration?
Solution
1
2
3
A.
B.
C.
D.
1,
1,
2,
2,
2,
3,
3,
1,
pH
4
12
9
3
2
1
3
(8) In which of the following compounds does strontium have the electron configuration of
a noble gas?
A.
B.
C.
D.
Sr2
SrCl
Sr2Cl
SrO
(9) Calcium cyanide is used in mining to isolate precious metals like silver and gold. How
many formula units of calcium cyanide can be formed from seven atoms of calcium, ten
atoms of carbon, and nine atoms of nitrogen?
A.
B.
C.
D.
3
4
5
7
(10) A double replacement reaction occurs between lithium sulfate and barium chloride. In
the balanced chemical equation for this reaction, which of the following would be the
products?
A.
B.
C.
D.
2LiCl +
2LiCl +
2LiCl +
2LiClO3
BaS
Ba(SH)2
BaSO4
+ BaSO4
2016-2017 Sample Questions – Chemistry Connections
Copyright 2017 Chemical Educational Foundation®
Answer Key
See how you did! Check out the answers below.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
C
D
D
D
B
B
C
D
B
C
Please note: CEF does not endorse or approve the use of any CEF Challenge questions for the purposes
of preparing for any level of the Challenge. Challenge competition questions (including the Challenge
Qualifier) are for competition purposes ONLY. Students should NOT receive or use questions (from the
current year or any previous years) at any point to study. Use of Challenge competition questions for
study purposes is grounds for disqualification.
2016-2017 Sample Questions – Chemistry Connections
Copyright 2017 Chemical Educational Foundation®