Unit 2: Advanced Basics

Section 2: Acid/Base Reactions

Acid/Base Reactions - Basics

Titration

Acid/Base Reactions - Basics

Acid/Base reactions are reactions that involve the neutralization of an acid through the use of a base. But what does that all mean? This means that when at solution of HCl and NaOH are reacted together, the acidity of the HCl will be reduced by NaOH (which is a strong base). In this reaction, the Na+ and the Cl- are called spectator ions because they play no role in the overall outcome of the reaction. The only thing that reacts is the H⁺ (from the HCl) and the OH^- (from the NaOH). So the reaction that actually takes place is:

If in the end, the OH^- was the limiting reagent and there are H⁺'s still left in the solution then the solution is acidic, but if the H⁺ was the limiting reagent and OH^-'s were left in the solution then the solution is basic.

Titration

Titration is the process of mixing acids and bases to analyse one of the solutions. For example, if you were given an unknown acidic solution and a 1 molar NaOH solution, titration could be used to determine what the concentration of the other solution was.

The goal of titration is to determine the equivalence point. The equivalence point is the point in which all the H⁺ and the OH^- ions have been used to produce water. Titration also usually involves an indicator. An indicator is a liquid that turns a specific color at a specific pH. (Different indicators change colors at different pH's) Indicators are chosen to allow a color change at the equivalence point.