What will happen when a reactant is added to a system at equilibrium?

A. More reactants will form.
B. The system will remain at equilibrium.
C. The equilibrium of the system will be upset.
D. Only the concentration of that reactant will change.

Question

What will happen when a reactant is added to a system at equilibrium?

 		A.	More reactants will form.
 		B.	The system will remain at equilibrium.
 		C.	The equilibrium of the system will be upset.
 		D.	Only the concentration of that reactant will change.

vera_ewing · Answer

@JFraser A or B?

jfraser · Answer

think of equilibrium like a see-saw that has to be kept in balance. If you overload one side, mass must $shift$ $away$ from the excess

vera_ewing · Answer

@JFraser So the equilibrium of the system will be upset?

jfraser · Answer

it will be, and what direction will it move in, if the reactants are upset?

vera_ewing · Answer

I'm not sure. Can you please explain?

jfraser · Answer

the reactants are "too heavy". in order to restore the balance, where does the mass move to?

jfraser · Answer

it has to be one one side or another

vera_ewing · Answer

The side with less reactants?

jfraser · Answer

the mass on the left is too large. to restore balance, the mass must move to the products

vera_ewing · Answer

Ohh okay so the answer is C?

jfraser · Answer

it is

vera_ewing · Answer

Thank you for explaining it! :)