Unit 7: Solutions, Acids, and Bases

The host introduces solutions, acids and bases and their importance in chemistry. The students begin a lab, adding different salts to water at different temperatures and observing the conditions under which the salts dissolve.

In this segment, the students learn about solubility, insolubility, and saturated solutions. They interpret the data they compiled during the lab on dissolving salts. In the classroom, the teacher tests several solutions, and they discuss the nature of chemical solutions.

Our host describes ways to express solution concentration. The class learns about mass percent and the students propose plans for creating solutions with a known molarity.

In segment D, the teacher and students discuss the results from the molarity lab and how to express concentrations using mass percent or molarity. The students learn how to work a dilution problem and create a plan for a lab during which they will perform a dilution to reach a specific molarity.

The students perform the dilution lab and discuss their results to understand how to make a concentrated solution more dilute using target volume and concentration, as well as accurate calculations.

The host discusses two of the colligative properties, freezing point depression and boiling point elevation. The students make ice cream to investigate colligative properties and solve problems to find the freezing point and boiling point of different substances. We also see how a Popsicle® manufacturer, King of Pops, makes their product.

In segment G, our host introduces acids and bases, two types of solutions made of chemical compounds. In the classroom, the students and teacher investigate the properties of acids and bases and test household substances with cabbage juice to see if they are an acid or a base.

The students use litmus paper to determine the acidity of different substances and discuss the Bronsted-Lowry Model, the Arrhenius Model, and the Lewis Model. They measure the pH of different substances in water. The host describes strong and weak acids and bases and performs a lab demonstrating neutralization reactions and titration. The students begin a titration lab.

In this segment, the students discuss the data from their titration lab. Our host explains the importance of titration in real world applications and discusses auto ionization of water and the calculation of pH.

The students explain how they calculated the pH of the acid used in the titration lab. The host explains how important the concepts in this unit are to chemistry. We hear an interview with Winston Eason, an agricultural extension agent with the state of Georgia, who discusses agricultural economics, the pH measurement of soil, organic farming, pesticides, and urban gardening.