Question

When you mix a light blue/green aqueous solution of copper (II) chloride with a solid piece of aluminum metal, what is an easy, VISUAL observation you could make to determine which reactant is in EXCESS vs. which reactant is the LIMITING REACTANT?

a) The color of the solution turns darker.
b) The solution becomes clear and transparent.
c) Bubbles are produced and a gas is released.
d) The solution turns yellow.

Answer 1

In the reaction between copper (II) chloride and aluminum, the easy visual observation to determine which reactant is in excess is the production of bubbles and release of a gas.

Step-by-step explanation:

The easy visual observation to determine which reactant is in excess vs. which reactant is the limiting reactant in the reaction between a light blue/green aqueous solution of copper (II) chloride and a solid piece of aluminum metal is the production of bubbles and release of a gas.

When aluminum reacts with copper (II) chloride, aluminum displaces copper from the compound and forms aluminum chloride. During this displacement reaction, hydrogen gas is also produced. The gas bubbles will indicate the presence of the excess reactant, which in this case, is the reactant that is not completely consumed.

Therefore, choice c) Bubbles are produced and a gas is released is the correct answer to determine which reactant is in excess.