Chemical Reactions and Equations
Practice Test
1.
What is the missing product in this balanced equation describing the decomposition of water? 2H
2
O(l) + energy
O
2
(g) +
a.
2H
2
(g)
b.
H
2
(g)
c.
H
2
O(g)
d.
energy
2.
Carbon dioxide is __________ in water.
a.
a solid
b.
soluble
c.
insoluble
d.
blue
3.
A sample of gold has a mass of 15.7 g and displaces 0.81 cm3 of water in a graduated cylinder. What is the density of gold?
a.
0.81 g/cm3
b.
14.9 g/cm3
c.
19.3 g/cm3
d.
.05 g/cm3
4.
What is the formula for the binary compound of potassium and chlorine?
a.
K2ClO3
b.
KHCl
c.
KCl
d.
KCl2
5.
Na
2
SO
4
is the formula for _______________.
a.
sodium sulfur oxide
b.
sodium sulfide
c.
sodium sulfate
d.
sodium sulfite
6.
Mendeleev saw that properties of the elements repeated in an orderly way when he organized them according to ______________.
a.
decreasing atomic number
b.
increasing atomic mass
c.
increasing volume
d.
increasing atomic size
7.
An explanation based on many observations and supported by the results of many experiments is called a _____________.
a.
theory
b.
hypothesis
c.
fact
d.
scientific law
8.
These elements have six electrons in their outermost energy levels.
a.
O, S, and Se
b.
Cr, Mn, and Fe
c.
He, Ne, and Ar
d.
Cr, Mo, and W
9.
This type of chemical reaction has energy written as a product.
a.
light-absorbing
b.
exothermic
c.
energy-absorbing
d.
endothermic
10.
Changes in an equilibrium system can be described according to _____________ principle.
a.
Le Chatelier's
b.
Dalton's
c.
Boyle's
d.
Rutherford's
11.
________________ indicate a state of equilibrium in a chemical equation.
a.
A plus sign
b.
Double reaction arrows
c.
An equal sign
d.
A minus sign
12.
Green plants take in this gas and give off oxygen during photosynthesis.
a.
nitrogen
b.
hydrogen
c.
ammonia
d.
carbon dioxide
13.
A ____________ reaction is one in which a compound breaks down into two or more simpler substances.
a.
replacement
b.
synthesis
c.
decomposition
d.
photosynthesis
14.
This is a metallic element that reacts violently with water.
a.
sodium
b.
iron
c.
silver
d.
copper
15.
A ____________ reaction is one in which one element takes the place of another in a compound.
a.
single displacement
b.
decomposition
c.
double displacement
d.
synthesis
16.
Most alpha particles in Rutherford's gold-foil experiment ________________________.
a.
passed straight through the foil
b.
bounced back
c.
were deflected at small angles
d.
were deflected at large angles
17.
Heavy elements such as seaborgium are created in _____________.
a.
particle accelerators
b.
erlenmeyer flasks
c.
earthquakes
d.
test tubes
18.
The statement that the physical and chemical properties of the elements repeat in a regular pattern when they are arranged in order of increasing atomic number is known as the ______________.
a.
periodic law
b.
Dobereiner's hypothesis
c.
Mendeleev theory
d.
Group theory
19.
A mystery compound dissolves in water to produce a solution that does not conduct electricity. The compound cannot be __________.
a.
sodium chloride
b.
ethanol
c.
benzene
d.
butane
20.
An object has a mass of 20.0 g and a volume of 10.0 mL. What is its density?
a.
20.0 g
b.
2.00 g/mL
c.
10.0 mL
d.
0.500 g/mL
