WorksheetsU8 Kinetics Practice Exam
Total questions: 31
Worksheet time: 18mins
A reaction is most likely to occur when reactant
particles collide with
proper energy, only
both proper energy and proper orientation
proper orientation, only
neither proper energy nor proper orientation
A chemical reaction between iron atoms and oxygen molecules can only occur if
the atmospheric pressure decreases
the particles are heated
there are effective collisions between the
particle
there is a catalyst present
After being ignited in a Bunsen burner flame, a
piece of magnesium ribbon burns brightly, giving
off heat and light. In this situation, the Bunsen
burner flame provides
heat of reaction
heat of vaporization
activation energy
ionization energy
As the temperature increases, the rate of an
exothermic reaction
decreases
increases
remains the same
In most aqueous reactions as temperature
increases, the effectiveness of collisions between
reacting particles
decreases
increases
remains the same
Each of four test tubes contains a different
concentration of HCI(aq) at 25°C. A 1-gram cube
of Zn is added to each test tube. In which test tube
is the reaction occurring at the fastest rate?
At 20.°C, a 1.2-gram sample of Mg ribbon reacts
rapidly with 10.0 milliliters of 1.0 M HCl (aq).
Which change in conditions would have caused the
reaction to proceed more slowly?
increasing the initial temperature to 25°C
decreasing the concentration of HCl (aq) to
0.1 M
using 1.2 g of powdered Mg
using 2.4 g of Mg ribbon
Given the reaction:
A2(g) +B2 (g) ↔ 2AB(g) + heat
An increase in the concentration of A2(g) will
increase the frequency of collisions between
A2(g) and B2(g)
decrease the production of AB(g)
decrease the frequency of collisions between
A2(g) and B2(g)
increase the production of B2(g)
Beaker A contains a 1 gram piece of zinc and
beaker B contains 1 gram of powdered zinc. If 100
milliliters of 0.1 M HCl is added to each of the
beakers, how does the rate of reaction in beaker A
compare to the rate of reaction in beaker B?
The rate in A is greater due to the larger
surface area of the zinc.
The rate in A is greater due to the smaller
surface area of the zinc.
The rate in B is greater due to the larger
surface area of the zinc.
The rate in B is greater due to the smaller
surface area of the zinc.
Which statement explains why the speed of some
chemical reactions is increased when the surface
area of the reactant is increased?
This change exposes more reactant
particles to a possible collision.
This change increases the density of the
reactant particles.
This change increases the concentration of
the reactant.
This change alters the electrical conductivity
of the reactant particles.
Given the balanced equation representing a phase
change:
C6H4Cl2(s) + energy → C6H4Cl2(g)
Which statement describes this change?
It is exothermic, and entropy decreases.
It is exothermic, and entropy increases.
It is endothermic, and entropy increases.
It is endothermic, and entropy decreases.
For a given reaction, adding a catalyst increases
the rate of the reaction by
using the same reaction pathway and
decreasing the activation energy
providing an alternate reaction pathway
that has a lower activation energy
providing an alternate reaction pathway that
has a higher activation energy
using the same reaction pathway and
increasing the activation energy
Based on the nature of the reactants in each of the
equations below, which reaction at 25°C will
occur at the fastest rate?
CaCO3(s) → CaO(s) + CO2(g)
NaOH(aq) + HCl(aq) →
NaCl(aq) + H2O(l )
C(s) + O2(g) → CO2(g)
CH3OH(liq ) + CH3COOH(liq ) →
CH3COOCH3(aq) + H2O(liq )
If a catalyst is added to a system at equilibrium
and the temperature and pressure remain
constant, there will be no effect on the
activation energy of the reaction
rate of the reverse reaction
heat of reaction
rate of the forward reaction
Which balanced equation represents an
endothermic reaction?
N2(g) + O2(g) → 2NO(g)
CH4(g) + 2O2(g) → CO2(g) + 2H2O( liq)
C(s) + O2(g) → CO2(g)
N2(g) + 3H2(g) → 2NH3(g)
Given the above balanced equation:
Which statement best describes this process?
It is endothermic and entropy decreases.
It is exothermic and entropy decreases.
It is exothermic and entropy increases.
It is endothermic and entropy increases.
A student observed that the temperature of water
increased when a salt was dissolved in it. The
student should conclude that dissolving the salt
was
an exothermic reaction
an endothermic reaction
involved in the formation of a basic solution
involved in the formation of an acidic
solution
Given the balanced equation:
Which phrase best describes this reaction?
endothermic with ΔH = –1640 kJ
endothermic with ΔH = +1640 kJ
exothermic with ΔH = +1640 kJ
exothermic with ΔH = –1640 kJ
According to Reference Table I, which statement
best describes the formation of HI(g)?
It is endothermic, and heat is released.
It is exothermic, and heat is released.
It is endothermic, and heat is absorbed.
It is exothermic, and heat is absorbed.
In a chemical reaction, the difference between the
potential energy of the products and the potential
energy of the reactants is called
activation energy
heat of reaction
kinetic energy
activated complex
The diagram above represents the energy changes
that occur during the formation of a certain
compound under standard conditions.
According to Reference Table I, the compound
could be
HI(g)
NH3(g)
CO2(g)
C2H6(g)
Given the reaction:
N2(g) + 2 O2(g) ↔2 NO2(g)
ΔH = + 7.9 kcal/mole
The potential energy diagram of the reaction is
shown above.
Which arrow represents the heat of reaction
(ΔH) for the reverse reaction?
1
2
3
4
The potential energy diagram of a chemical
reaction is shown above. Which arrow represents the part of the reaction
most likely to be affected by the addition of a
catalyst?
A
B
C
D
Given the equation representing a reaction:
N2O4 (g) ↔ 2NO2(g)
Which statement describes this reaction at
equilibrium?
The rate of the forward reaction is greater
than the rate of the reverse reaction.
The concentration of N2O4(g) must equal the
concentration of NO2(g).
The rate of the reverse reaction is greater
than the rate of the forward reaction.
The concentration of N2O4(g) and the
concentration of NO2(g) must be constant.
A chemical reaction is at equilibrium. Compared
to the rate of the forward reaction, the rate of the
reverse reaction is
faster and more product is produced
faster and more reactant is produced
the same and the reaction continues in
both directions
the same and the reaction has stopped
Given the balanced equation, which represents
the Haber process:
N2(g) + 3 H2(g) ↔ 2 NH3(g)
Which effect will an increase of pressure have on
the system?
a decrease in the amount of NH3 and a
decrease in the amount of N2
an increase in the amount of NH3 and a
decrease in the amount of N2
an increase in the amount of NH3 and an
increase in the amount of N2
a decrease in the amount of NH3 and an
increase in the amount of N2
Given the reaction at equilibrium:
N2(g) + O2(g) + energy ↔2 NO(g)
Which change will result in a decrease in the
amount of NO(g) formed?
increasing the concentration of O2(g)
decreasing the pressure
increasing the temperature
decreasing the concentration of N2(g)
Given the equilibrium reaction at constant
pressure:
2 HBr(g) + 17.4 kcal ↔ H2(g) + Br2(g)
When the temperature is increased, the
equilibrium will shift to the
left, and the concentration of HBr(g) will
decrease
right, and the concentration of HBr(g)
will decrease
left, and the concentration of HBr(g) will
increase
right, and the concentration of HBr(g) will
increase
Systems in nature tend to undergo changes
toward
higher energy and lower entropy
lower energy and lower entropy
higher energy and higher entropy
lower energy and higher entropy
Which reaction has the greatest increase in
entropy?
2 H2O(g) → 2 H2(g) + O2(g)
H2O(liq) → H2O(s)
H2O(g) → H2O(liq )
2 H2O(liq ) → 2 H2(g) + O2(g)
Nitrogen gas, hydrogen gas, and ammonia gas are in equilibrium in a closed container at constant temperature and pressure. The equation below represents this equilibrium.
N2(g) + 3H2 ↔ 2NH3(g)
The graph below shows the initial concentration of each gas, the changes that occur as a result of adding H2(g) to the system, and the final concentrations when equilibrium is reestablished.
Explain, in terms of collision theory, why the concentration of H2(g) begins to decrease
immediately after more H2(g) is added to the system.
