Complete Whole Notebook

Explanation: With the addition of the catalyst it will allow the amount of energy required to be less
than what it was originally was. Resulting in an increase rate of the reaction.
3 For the reaction
A + (aq) + B — (aq) → AB (s)
Increasing the temperature increases the rate of the reaction. Which is the best explanation for this
happening?
A The pressure increases, which in turn increases the production of products.
B The concentration of reactants increases with an increase in temperature.
C The average kinetic energy increases, so the likelihood of more effective collisions between ions
increases.
D Systems are more stable at high temperatures.
Explanation: When you increase the surface area, more of the substances is exposed to particles
which in turn will increase the collision of particles that cause the reaction. Therefore, this will result in
an increase in the speed of some reactions. Particles can only react when they collide. If you heat a
substance, the particles move faster and so collide more frequently. That will speed up the rate of
reaction. Collisions only result in a reaction if the particles collide with enough energy to get the
reaction started. This minimum energy required is called the activation energy for the reaction.
4 Which statement explains why the speed of some reactions is increased when the surface area of
one or all the reactants is increased?
A increasing surface area changes the electronegativity of the reactant particles
B increasing surface area changes the concentration of the reactant particles
C increasing surface area changes the conductivity of reactant particles
D increasing surface area enables more reactant particles to collide
Explanation: The more finely divided the solid is, the faster the reaction happens. A powdered solid
will normally produce a faster reaction than if the same mass is present as a single lump. The
powdered solid has a greater surface area than the single lump. You are only going to get a reaction
if the particles in the gas or liquid collide with the particles in the solid. Increasing the surface area of
the solid increases the chances of collision taking place. Increasing the number of collisions per
second increases the rate of reaction.
catalyst
C6H6 + Br2 → C6H5Br + HBr
5 Which of the following changes will cause an increase in the rate of the above reaction?
A increasing the concentration of Br2
B decreasing the concentration of C6H6
C increasing the concentration of HBr
D decreasing the temperature
Explanation: The same argument applies whether the reaction involves collision between two
different particles or two of the same particle. In order for any reaction to happen, those particles
must first collide. This is true whether both particles are in solution, or whether one is in solution and
the other a solid. If the concentration is higher, the chances of collision are greater. For many
reactions involving liquids or gases, increasing the concentration of the reactants increases the rate
of reaction. In a few cases, increasing the concentration of one of the reactants may have little
noticeable effect of the rate.
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