When reactants (LHS substances) are removed from a chemical reaction at equilibrium ...

Question

When reactants (LHS substances) are removed from a chemical reaction at equilibrium ... 

a) The equilibrium shifts to the LHS

b) The equilibrium is not changed

c)None of these

d) The equilibrium shifts to the RHS

Answer 1

When reactants (LHS substances) are removed from a chemical reaction at equilibrium ... 

The answer is a) The equilibrium shifts to the LHS

The easiest way to understand Le Chatelier's principle in equilibrium reactions is to think of the whole reaction (reactants and products) as being attached to a rope.

You want to think of removing something from one side as the rope being pulled in that direction.

Consequently, you can think of adding something to one side as pushing the rope to the other side.

Visually, we can use arrows to further express this concept. Suppose we have the following:

Α + B ⇌ C + D

If we remove some of B, this rope concept can be expressed like this:

←— ←—_(-B) ←— ←—

←—Α—— + ^↖︎—B—— ⇌ ——C—→ + ——D—→

As a result of B being removed, the 'rope' will be 'pulled' in the same direction B is being removed:

←—Α— ←—B— ⇌ ←—C— ←—D—

The result of everything shifting to the left, (LHS for left hand side)

Answer 2

LHS = left hand side? this is not an authorized acronym.

Based on the La Chatelier's principle, the system shifts in a direction that minimizes the disturbance, in another word, it (the equilibrium) bounces back...

therefore, the stress caused by removing the reactants will be on the product side. To minimize the stress, the amount of products should decrease and the amount of reactant increases as it bounces back.

The answer is a)