Question

Will FAN & MEDAL!!!!
Which statement correctly describes a chemical equilibrium?
It must take place in an open system.
The mass of the reactants and the mass of the products are not equal.
It is affected by the addition of a catalyst.
It does not involve a reversible reaction.
The concentrations of reactants and products are equal.

Answer 1

The catalyst does not affect the equilibrium because it lowers the activation energies of both the forward and reverse reactions.

Answer 2

Reversible reactions lead to equilibrium,
The rate of the forward and reverse reactions are equal to each other but that does not necessarily mean that they are equal, although they can be depending on the value of your Keq.
I think Chem equilibrium can take place only in a closed system.

Answer 3

The concentrations of the reactants and products are equal would be the best choice b/c it describes a state where Keq equilibrium constant = 1