Chem Notebook COmplete

Chemical Concepts:
The chemical concepts which are tied with this question are “catalyst”, “activation energy”, and “rate
of reaction”. Activation energy is defined as the minimum amount of energy a reactant needs to
obtain in order for the reaction to take place. A catalyst is known as an agent added into a reaction
that causes the required activation energy to be lowered; therefore, the reaction occurs at a faster
rate and requires less energy. Finally, reaction rate is described as the measurement and relationship
of time and the amount of products formed by the reactants in a reaction.
10 When a reaction is at equilibrium and more reactant is added, which of the following changes is
the immediate result?
A The reverse reaction rate remains the same.
B The forward reaction rate increases.
C The reverse reaction rate decreases.
D The forward reaction rate remains the same.
Chemical Concepts:
This question contains the chemical concepts of “equilibrium”, the “reactant”, and “forward/reverse
reaction”. Equilibrium is the condition of a reaction where the changing of reactant particles and the
product particles are no longer being exhibited at separate rates, the inclination to change from one
another as time continues passing, this standstill and levelness in concentration of both sides is
known as “EQUILIBRIUM”. A reactant is the substance that changes into something else, the
product, during the manifestation of the reaction. The forward reaction describes the change of a
substance from reactant to product; reverse reaction, on the other hand, describes the change of a
substance from a product into a reactant.
11 In which of the following reactions involving gases would the forward reaction be favored by an
increase in pressure?
A A + B ⇄AB
B A + B ⇄ C + D
C 2A + B ⇄ C + 2D
D AC ⇄ A + C
Chemical Concepts:
The chemical concepts involved with this question are “pressure” and “Le Châtelier's principle”. Le
Chatelier’s principle declares that a system that has reached equilibrium can be disrupted and
derived from equilibrium through the use of a stressing agent, which can be a force that suddenly
changes. One of these changes in conditions that tilts the fine balance found in dynamic equilibrium is
pressure. Pressure is the application of a constant force on an object or substance. Changes in the
pressure of a reaction during dynamic equilibrium, can again resume the difference in rates of
reactants to products, and products to reactants. This is the case because the proximity between
particles can either extend or decrease making it more likely or less likely for collision to occur,
changing the forward and reverse reactions.
4HCl (g) + O 2(g) ⇄ 2H 2 O (l) + 2Cl 2(g) + 113 kJ
12 Which action will drive the reaction to the right?
A heating the equilibrium mixture
B adding water to the system
C decreasing the oxygen concentration
D increasing the system’s pressure