Question

Reactions only occur until one of the reactants run out. This is referred to as the limiting reactant. Today, we are going to make a lava lamp using an Alka seltzer tablet. The material is water, oil,and Alka seltzer.Identify what reaction is occurring and what the limiting reactant is.

Answer 1

Alka seltzer contains sodium bicarbonate as main ingredient which reacts with water as below

Since the lava lamp is an experiment where water droplets along with CO2 liberated enters the oil layer to form bubbles. Hence production of CO2 is important. The production of CO2 depends on amount of Bicarbonate added. Hence sodium bicarbonate is the limiting reagent.

In other words water is taken in excess amount while Sodium bicarbonate added to it gets vanishes once reaction is complete. Hence more and more sodium bicarbonate must be added to the mixture of oil and water which means the sodium bicarbonate is utilised completely. Hence its the limiting reagent.