Bellringer What is an acid? What is a base? What are some properties of an acid? What are some properties of a base?

Strength of Acids and Bases

What makes a strong acid or base? Sulfric acid in a car battery can burn you, but does the citric acid in orange juice? The strength of an acid or base is based on how many acid or base particles break down into ions in water. When a strong acid dissolves in water nearly all of the acid molecules will break down into ions When a weak acid dissolves in water, only a small fraction of the molecules dissolve in water This is the same for bases Ions in a solution can conduct electricity, so strong acids and bases will conduct electricity well

Strength vs. Concentration Strong and weak are terms used to describe how well the substance break down in water Concentrated or dilute are terms used to indicate the amount of an acid or base dissolved in a solution It is possible to have a dilute solution of a strong acid or base and a concentrated solution of a weak acid or base

pH of a Solution pH is the measure of the concentration of hydrogen ions (H+) in a solution The more hydrogen ions you have in a solution, the lower the pH is and the more acidic the solution is pH lower than seven is acidic, while pH higher than 7 is basic. pH of 7 is neutral

Measuring pH Litmus paper is one way to measure pH. The paper undergoes a color change in the presence of hydrogen and hydronium ions. The color is then compared to a chart. A pH meter uses electrical conductivity to measure pH Red cabbage juice contains a natural pH indicator. Acids will turn it pink while bases will turn it green

Buffers Buffers are weak acids or bases that are added to a solution to prevent a change in pH Buffers are present in your blood to keep the pH between 7 and 7.8