There are many different types of chemical reactions that occur daily. However, every reaction has a different rate. A rate is defined as a measure of change over time. Chemists study these rates of reactions to help them understand how these chemical reactions can be controlled. Chemical reactions occur when reactants come in contact with each other. This lab observed the chemical reaction between two Alka-Seltzer tablets and water. Alka-Seltzer tablets are used to treat aches in the body, acid refluxes and stomach ingestions. Alka-Seltzer tablets contain crystals of sodium bicarbonate and citric acid. These crystals do not interact with each other in their dry states, however, when an Alka-Seltzer tablet is dropped in water a