Which of the following statements is true for a system at chemical equilibrium?

a. the system releases energy at a steady rate.
b. the system can do no work.
c. the system consumes energy at a steady rate.
d. the kinetic energy of the system is zero.

Option B is true: The system can do no work

Explanation:

a. The system releases energy at a steady rate. False

In thermodynamic equilibrium there are no net macroscopic flows of matter or of energy, either within a system or between systems.

b. The system can do no work. True

If the connection between the systems allows transfer of energy as heat but does not allow transfer of matter or transfer of energy as work, the two systems may reach thermal equilibrium without reaching thermodynamic equilibrium.

c. The system consumes energy at a steady rate. False.

In thermodynamic equilibrium there are no net macroscopic flows of matter or of energy, either within a system or between systems.

d. The kinetic energy of the system is zero. False.

At maximum displacement from the equilibrium point, potential energy is a maximum while kinetic energy is zero. At the equilibrium point the potential energy is zero and the kinetic energy is a maximum. At other points in the motion the oscillating body has differing values of both kinetic and potential energy.

yes the answer is total mass in unchanged   : )