Question

question 9 (1 point)
a system has reached chemical equilibrium. which is true of the system?
a) there is no net change in the concentration of reactants or products
b) the molecules have stopped combining and decomposing
c) the system is open
d) there is no change taking place
e) all of the above are true

Explanation:

To solve this, we analyze each option based on the concept of chemical equilibrium:

• Option a: 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. This is correct.
• Option b: Molecules are still combining (forward reaction) and decomposing (reverse reaction) at equilibrium, just at equal rates. So this is incorrect.
• Option c: A system at chemical equilibrium is typically a closed system (to maintain constant concentrations of reactants and products). An open system would allow matter to enter or leave, disrupting equilibrium. So this is incorrect.
• Option d: While there's no net change, the forward and reverse reactions are still occurring (dynamic equilibrium), so there are changes (just no net change). Thus, this is incorrect.
• Option e: Since b, c, and d are incorrect, this is also incorrect.

Answer:

a) there is no net change in the concentration of reactants or products