WorksheetsChem: Pre-Test
Total questions: 60
Worksheet time: 41mins
Which of the following describes a natural phenomenon but does not explain it?
scientific law
analytical chemistry
theory
hypothesis
You are trying to identify an unknown, bright blue solution. Because some solutions of copper salts have a blue color, you decide to run tests for copper. Which of the following terms best describes this process?
applying a scientific law
building a model
confirming a theory
testing a hypothesis
Which state of matter is the hardest to compress?
solid
liquid
gas
none of the above
Jami has a liquid substance. She notices that the liquid has all of the following characteristics except for which of the following?
a definite shape
expands when heated
a fixed volume
can flow
Table salt contains the elements sodium and chlorine. Identify the chemical formula of this compound.
NaCl
SCl
SoCl
NaCh
To write 0.0000054 in scientific notation, you should move the decimal point
7 places to the right
7 places to the left
6 places to the right
6 places to the left
Identify the smallest value.
2.3 × 107
2.3 × 105
2.3 × 10−1
2.3 × 10−7
How many milliliters is equivalent to 20 cubic centimeters of a substance?
2 mL
20 mL
200 mL
2000 mL
The boiling point of potassium is 760°C. What is the boiling point of potassium in kelvins?
1033 K
487 K
760 K
0 K
Iron has a density of 0.00787 kg/cm3. What is the density of iron in grams per cubic centimeters?
A 787 g/cm3
B 78.7 g/cm3
C 7.87 g/cm3
D 0.787 g/cm3
An ion with a net charge of 2+ loses 5 electrons. What is its charge?
7+
3+
3 -
7 -
An ion with a charge of 4− loses 4 electrons. What is its charge?
neutral
-16
8-
8+
What is the total number of subatomic particles (protons, electrons, and neutrons) in an atom of potassium-39?
19
20
39
58
Which pair of orbitals has the same shape?
2s and 4p
2s and 3p
3p and 4f
2s and 4s
What atom has a ground state electron configuration of 1s22s22p63s23p4?
magnesium
nitrogen
oxygen
sulfur
As you read left to right across a period, the atomic size of the elements generally
double
stays the same
increases
decreases
Which element has the greatest electronegativity value?
magnesium
carbon
fluorine
potassium
For which groups of elements are data plotted on graphs 1 and 2, respectively?
alkaline earth metals and noble gases
alkali metals and halogens
alkaline earth metals and halogens
alkali metals and metalloids
How many valence electrons do the elements in Group 6A (from the periodic table) have?
8
6
2
0
The binary molecular compound, KCl4, contains 4 chlorine atoms. When naming the compound, what prefix is associated with 4 atoms?
mono-
tri-
tetra-
hexa-
If you see –ide at the end of a chemical name, what can you assume?
it is a binary compound
it is an acid
it has a neutral charge
it is a polyatomic ion
Which compound name ends in a suffix other than –ate?
K3CO3
LiNO3
MgSO4
NH4Cl
About how many moles is 1.2 × 1018 atoms of tin?
2 × 10−6 moles
5 × 10−6moles
5 × 1016 moles
7 × 1041 moles
Which conversion factor would you use first to find the number of molecules in 4.6 mol of glucose, C6H12O6?
A
B
C
D
What is the percent by mass of carbon in trichloropropane, C3H6Cl3?
12.0%
24.2%
8.09%
25.0%
NaHCO3(s) + HCl(aq) → NaCl(aq) + H2O(l) + CO2(g)
What is meant by the arrow in the reaction?
equals
yields
energy
equilibrium
NaHCO3(s) + HCl(aq) → NaCl(aq) + H2O(l) + CO2(g)
What are the reactants of the equation?
NaCl, H2O
H2O, CO2
NaHCO3, HCl
NaCl, H2O, CO2
NaHCO3(s) + HCl(aq) → NaCl(aq) + H2O(l) + CO2(g)
Which of the products is in the gaseous state?
HCl
NaCl
CO2
H2O
Balance the following chemical equation. What is the coefficient for H2O?
C3H8 + O2 → CO2 + H2O
2
3
4
5
If you increase the volume of a gas while keeping the temperature constant, what will happen to the pressure?
The pressure will stay the same
The pressure will increase
The pressure will decrease
The pressure will double
Boyle’s Law states that P1×V 1 = P2 × V2 at a constant temperature.
A lab technician has 75 L gas in a contained cylinder at a pressure of 60 kPa. If the technician increases the pressure to 100 kPa, without changing the temperature, what is the new volume?
150 L
125 L
75 L
45 L
A 25 L sample of nitrous oxide at 335 K is cooled to 300 K, under a constant pressure. Which of the following best describes the new volume?
less than 25 L
more than 25 L
exactly 25 L
cannot be determined
What ratio is used to covert liters of H2O2 to mol H2O2 at standard temperature and pressure?
A
B
C
D
What conversion factor can be used to convert molecules of water to grams of water?
A
B
C
D
What is the name of the phase transition indicated by (a)?
sublimation
vaporization
freezing
condensation
What is the name of the phase transition indicated by (a)?
sublimation
vaporization
freezing
condensation
Which explains why an ice cube floats in a glass of water?
The density of water in a solid state is less than the density of water in a liquid state.
The mass of a glass of water is greater than the mass of an ice cube.
The specific gravity of an ice cube is greater than that of the liquid state of water.
The hydrogen bonds between solid water molecules are weaker than those of liquid molecules.
Which of the following substances will readily dissolve in water?
grease
gasoline
sucrose
oil
Which of these statements describes every solution?
The solute is a solid and the solvent is a liquid.
The solution is visually different from the solvent.
The solute particles are dispersed in the solvent.
The solute particles collect at the bottom of the solvent.
What happens when a salt crystal dissolves in water?
The crystal breaks into smaller crystals.
The ions of the salt crystal are separated by molecules of water.
The salt molecules form covalent bonds with each other.
The water molecules form ionic bonds with the salt molecules.
Which of these would increase the rate of sugar dissolving in water?
Grind the sugar into a fine powder and decrease the pressure.
Grind the sugar into a fine powder and increase the temperature of the water.
Lower the temperature of the water and increase the pressure.
Raise the temperature of the water and decrease the pressure.
The diagram shows the energy change that occurs as reactants are chemically changed to products. Assuming no work is done during this reaction, which statement(s) about the reaction diagram is (are) correct?
I. Heat is released to the surroundings.
II. The reactants have more stored chemical energy than the products.
III. This is an exothermic reaction.
I only
I and II only
I and III only
I, II, and III
The amount of heat needed to increase the temperature of an object by exactly 1°C is the object’s
specific heat
heat of vaporization
enthalpy
heat capacity
How many kilojoules of energy are released when 12.0 g of methane, CH4, are burned?
CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) ΔH= −890 kJ/mol
890 kJ
668 kJ
445 kJ
74.2 kJ
Which of these conditions will generally increase the rate of a chemical reaction?
Increased concentration of reactants, increased temperature, and decreased particle size
Increased concentration of reactants, decreased temperature, and increased particle size
Increased concentration of reactants, increased temperature, and increased particle size
Decreased concentration of reactants, increased temperature, and decreased particle size
A substance that increases the rate of a chemical reaction without undergoing a chemical change itself is a(n)
activated complex
catalyst
chemical activator
reaction intermediate
Which change would cause the equilibrium for this reaction to shift to the right?
Add H2.
Increase the size of the container.
Decrease the temperature.
Remove H2O(g).
Le Châtelier’s principle is used to
calculate equilibrium concentrations of reactants and products.
estimate the rate of a chemical reaction.
predict the spontaneity of a reaction.
predict how changing conditions affect the equilibrium position.
Which of the following statements accurately describes acids and bases?
acids are hydrogen ion donors and bases are hydrogen ion acceptors
acids donate electron pairs to bases
hydrogen is found in acids and not bases
water can act as an acid, but not a base, in an acid/base reaction
16. In a blast furnace, carbon, in the form of coke, is oxidized. What is reduced?l
limestone
Fe2O3 in iron ore
molten iron
carbon dioxide
All of these reactions are redox reactions EXCEPT
2Mg(s) + O2(g) → 2MgO(s)
Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq)
Ba(NO3)2(aq) + Na2SO4(aq) →2NaNO3(aq) + BaSO4(s)
Cl2(g) + H2O(l) → HCl(aq) + HClO(aq)
In which of the following would you find ONLY covalent bonds?
CaCO3
CH3NH2
MgI2
(NH4)3PO4
The –OH functional group in an alcohol molecule is called a(n)
carbonyl
aldehyde
oxidation
hydroxyl
Balance the equation below and identify the atom being reduced.
K2Cr2O7 + H2O + S → SO2 + KOH + Cr2O3
A 2K2Cr2O7 + H2O + 3S → 3SO2 + 4KOH + 2Cr2O3 Atom reduced is chromium.
A 2K2Cr2O7 + 2H2O + S → SO2 + 4KOH + 2Cr2O3 Atom reduced is chromium.
A 2K2Cr2O7 + 2H2O + 3S → 3SO2 + 4KOH + Cr2O3 Atom reduced is potassium.
A K2Cr2O7 + 2H2O + 3S → 3SO2 + 4KOH + Cr2O3 Atom reduced is potassium.
Which alcohol has the least solubility in any given proportion of water?
Methanol: CH3OH
Ethanol: C2H5OH
Phenol: C6H5OH
Isopropyl alcohol: C3H6OH
What is the process called that takes in light-energy and converts it into chemical energy?
combustion
metabolism
photosynthesis
hydration
Complete this energy equation:
___ + 6O2 → 6CO2 + 6H2O + Energy
C6H12O6
6CO2
H2CO3
12H2O
The atom of polonium-218 emits an alpha particle. The radioisotope formed emits a beta particle. What radioisotope is formed from this two-step decay process?
lead-214
thallium-211
lead-213
bismuth-214
What is the half-life of technetium-104?
72 minutes
36 minutes
16 minutes
54 minutes
What mass of technetium-104 remains after 96 minutes?
0 g
1 g
2 g
4 g
