OCHEMISTRY B- FINAL EXAM
QUESTIONS AND ANSWERS GRADED
A+
What happens when there is an increase in temperature for a reaction rate?
Select all that apply. - It increases the total number of molecular collisions that occur
It increases the percentage of collisions that result in a reaction
What is latent heat of condensation? - the amount of heat released when a certain mass of a substance
changes from a gas to a liquid
The greater the average kinetic energy of the particles in a sample of matter, __________. - the higher
the temperature
Why do water molecules tend to stick to each other to form a liquid? - The exposed charge on
hydrogen's protons are attracted to unshared electron pairs on oxygen atoms.
A solution is formed by dissolving 83.2 grams of copper II chloride (CuCl22) in 2.5 liters of water. The
molar mass of CuCl22 is 134.45 g/mol.
What is the molarity of the solution? - 0.25
A mixture consists of 45% oxygen, 12% argon, and 43% nitrogen by volume. A sample of this mixture has
a pressure of 2.0 atm in a 5.3 L container at 350 K temperature. How many moles of gas are in the
container? - 0.369
What type of reaction is shown in the graph, and why? - Exothermic: Energy is released to the
environment during the formation of the products.
, Examine the image, which shows four chemical systems of colliding molecules. Which chemical system
has the highest reaction rate? - D
Study the following equation.Fe(s) + 2 HCl(aq) ⇌ H22(g) + FeCl22(aq)
What happens to the iron metal when it is reacted in a closed container to produce hydrogen gas in this
manner?
Select all that apply. - The rate of the forward reaction is at its maximum when the reaction first starts.
The rate of the reverse reaction increases as hydrogen gas accumulates.
Magnesium metal reacts with oxygen according to the equation:Mg(s) + O22(g) → 2MgO22(s)
Which of the following would increase the rate of the reaction? - grinding the magnesium metal into a
fine powder
Examine the table.
What is the average half-life for the radioactive isotopes listed in the table? - 2.67 x 10^4 years
Study the reaction.H22SO44(l) + CaCO33(s) ⇌ CO22(g) + H22O(l) + CaSO44(aq)
Which of the following would cause the equilibrium to shift, producing more carbon dioxide gas?
Select all that apply. - removing water from the system
adding CaCO33 to the system
removing carbon dioxide gas from the system
What is true at chemical equilibrium? - the forward reaction rate is equal to the reverse reaction rate
A sample of a substance burns more rapidly in pure oxygen than in air. Which factor is most responsible
for this high rate of reaction? - the concentration of the reactants
QUESTIONS AND ANSWERS GRADED
A+
What happens when there is an increase in temperature for a reaction rate?
Select all that apply. - It increases the total number of molecular collisions that occur
It increases the percentage of collisions that result in a reaction
What is latent heat of condensation? - the amount of heat released when a certain mass of a substance
changes from a gas to a liquid
The greater the average kinetic energy of the particles in a sample of matter, __________. - the higher
the temperature
Why do water molecules tend to stick to each other to form a liquid? - The exposed charge on
hydrogen's protons are attracted to unshared electron pairs on oxygen atoms.
A solution is formed by dissolving 83.2 grams of copper II chloride (CuCl22) in 2.5 liters of water. The
molar mass of CuCl22 is 134.45 g/mol.
What is the molarity of the solution? - 0.25
A mixture consists of 45% oxygen, 12% argon, and 43% nitrogen by volume. A sample of this mixture has
a pressure of 2.0 atm in a 5.3 L container at 350 K temperature. How many moles of gas are in the
container? - 0.369
What type of reaction is shown in the graph, and why? - Exothermic: Energy is released to the
environment during the formation of the products.
, Examine the image, which shows four chemical systems of colliding molecules. Which chemical system
has the highest reaction rate? - D
Study the following equation.Fe(s) + 2 HCl(aq) ⇌ H22(g) + FeCl22(aq)
What happens to the iron metal when it is reacted in a closed container to produce hydrogen gas in this
manner?
Select all that apply. - The rate of the forward reaction is at its maximum when the reaction first starts.
The rate of the reverse reaction increases as hydrogen gas accumulates.
Magnesium metal reacts with oxygen according to the equation:Mg(s) + O22(g) → 2MgO22(s)
Which of the following would increase the rate of the reaction? - grinding the magnesium metal into a
fine powder
Examine the table.
What is the average half-life for the radioactive isotopes listed in the table? - 2.67 x 10^4 years
Study the reaction.H22SO44(l) + CaCO33(s) ⇌ CO22(g) + H22O(l) + CaSO44(aq)
Which of the following would cause the equilibrium to shift, producing more carbon dioxide gas?
Select all that apply. - removing water from the system
adding CaCO33 to the system
removing carbon dioxide gas from the system
What is true at chemical equilibrium? - the forward reaction rate is equal to the reverse reaction rate
A sample of a substance burns more rapidly in pure oxygen than in air. Which factor is most responsible
for this high rate of reaction? - the concentration of the reactants
