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What is a Solution?

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.

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.

Premiere Date: August 7, 2016 | Runtime: 00:11:51

Support Materials


Solubility Lab
Unit 7A Note Taking Guide & Questions

Crosscutting Concepts

System and System Models

Defining the system under study—specifying its boundaries and making explicit a model of that system—provides tools for understanding and testing ideas that are applicable throughout science and engineering.


Observed patterns of forms and events guide organization and classification, and they prompt questions about relationships and the factors that influence them.

Cause and Effect

Mechanism and explanation. Events have causes, sometimes simple, sometimes multifaceted. A major activity of science is investigating and explaining causal relationships and the mechanisms by which they are mediated. Such mechanisms can then be tested across given contexts and used to predict and explain events in new contexts.

Science & Engineering Practices

Asking Questions and Defining Problems

Students at any grade level should be able to ask questions of each other about the texts they read, the features of the phenomena they observe, and the conclusions they draw from their models or scientific investigations. For engineering, they should ask questions to define the problem to be solved and to elicit ideas that lead to the constraints and specifications for its solution. (NRC Framework 2012, p. 56)

Constructing Explanations and Designing Solutions

The goal of science is the construction of theories that provide explanatory accounts of the world. A theory becomes accepted when it has multiple lines of empirical evidence and greater explanatory power of phenomena than previous theories.”(NRC Framework, 2012, p. 52)

Generating a Hypothesis and Developing a Model

Modeling can begin in the earliest grades, with students’ models progressing from concrete “pictures” and/or physical scale models (e.g., a toy car) to more abstract representations of relevant relationships in later grades, such as a diagram representing forces on a particular object in a system. (NRC Framework, 2012, p. 58)

Planning and Carrying Out Investigations

Students should have opportunities to plan and carry out several different kinds of investigations during their K-12 years. At all levels, they should engage in investigations that range from those structured by the teacher—in order to expose an issue or question that they would be unlikely to explore on their own (e.g., measuring specific properties of materials)— to those that emerge from students’ own questions. (NRC Framework, 2012, p. 61)


acid - substances that ionize in solutions to form H^+ ions.

amphoteric - a substance that can be an acid or a base.

Arrhenius Model - in aqueous solutions, acids form hydrogen ions (H^+).

base - substances that ionize in solutions and form OH^- ions.

binary acids - acids that do not contain oxygen in their chemical formula.

boiling point elevation - occurs when the boiling point of a solution is higher than the boiling point of the pure solvent alone.

Bronsted-Lowry Model - this model states that any compound that can transfer a proton to any other compound is an acid, and the compound that accepts the proton is a base.

colligative properties - properties of the solution that are different than those of a pure solvent by itself.

dilution - the process of adding more solvent to a solution.

electrolysis - the decomposition of water.

freezing point depression - a colligative property that describes how the freezing point of a solution is lowered compared to the freezing point of the pure solvent.

heterogeneous mixture - a combination of two or more substances in which the original substances are separated into physically distinct regions with differing properties.

homogeneous mixture - a combination of two or more substances that have uniform composition and chemical properties throughout; also known as a solution.

insoluble - a solid, liquid, or gas that will not dissolve in a particular solvent.

Lewis Model - bases donate pairs of electrons and acids accept pairs of electrons.

mass percent - a way of expressing how concentrated a solution is; is equal to the mass of the solute in a solution divided by the total mass of the solution and multiplying by 100.

mixture - a combination of two or more pure substances in which each pure substance retains its individual chemical properties.

molality - a ratio of moles of solute to the mass of the solvent in kilograms.

molarity - a ratio of moles of solute to the volume of the solution in liters.

oxyacids - acids that contain oxygen in their chemical formula.

pure substance - a material that has a constant composition and has consistent properties throughout the sample.

saturated solution - a solution in which the maximum amount of solute has been dissolved in a given amount of solvent at a particular temperature.

saturation point - the point at which no more solute can be dissolved in the solution at that particular temperature.

solubility - the maximum amount of a substance that can be dissolved in a given quantity of solvent at a given temperature to produce a saturated solution.

solute - the substance that is being dissolved in a solution.

solution - a liquid mixture in which the solute is uniformly distributed within the solvent.

solvent - the substance that is present in a greater amount in a solution.

supersaturated solution - a solution that is holding more dissolved solute than what it normally would hold at that temperature. 

Georgia Standards of Excellence


Obtain, evaluate, and communicate information about the properties that describe solutions and the nature of acids and bases.


Develop a model to illustrate the process of dissolving in terms of solvation versus dissociation.


Plan and carry out an investigation to evaluate the factors that affect the rate at which a solute dissolves in a specific solvent.

Request Teacher Toolkit

The Chemistry Matters teacher toolkit provides instructions and answer keys for labs, experiments, and assignments for all 12 units of study. GPB offers the teacher toolkit at no cost to Georgia educators. Complete and submit this form to request the teacher toolkit. You only need to submit this form one time to get materials for all 12 units of study.