Question

question 1 (1 point)
a reversible reaction ______.
○ consists only of a forward reaction
○ consists only of a reverse reaction
○ consists of both a forward and a reverse reaction
○ consists of neither a forward nor a reverse reaction
○ none of the above

question 2 (1 point)
a system has reached chemical equilibrium. which is true of the system?
○ there is no net change in the concentration of reactants or products
○ the molecules have stopped combining and decomposing
○ the system is open
○ there is no change taking place
○ all of the above are true

question 3 (1 point)
which does not remain constant when a system is at dynamic equilibrium?
○ pressure
○ molecular reactions
○ temperature
○ concentration
○ ph

Explanation:

• Question 1: By definition, a reversible reaction can proceed in both the forward and reverse directions. So it consists of both a forward and a reverse reaction.
• Question 2: At chemical equilibrium, the rate of the forward reaction equals the rate of the reverse reaction. So there is no net change in the concentration of reactants or products. The molecules do not stop combining and decomposing (it is a dynamic process), the system is usually closed (not open), and there are changes (forward and reverse reactions) but no net change.
• Question 3: At dynamic equilibrium, pressure, temperature, concentration, and \(pH\) (if relevant) remain constant. Molecular reactions (forward and reverse) are still occurring (it is a dynamic state, not a static one where reactions stop).

Answer:

• Question 1: consists of both a forward and a reverse reaction
• Question 2: there is no net change in the concentration of reactants or products
• Question 3: molecular reactions