Introduction to Solutions Day 1 - Notes Introduction to Solutions

After today you will be able to… Explain the differences between the three different types of solutions Describe how to make a supersaturated solution Describe how to increase the rate of dissolving

SPI 3221.2.2 Identify properties of an aqueous solution including: STANDARD SPI 3221.2.2 Identify properties of an aqueous solution including: Colligative properties, procedure to determine the concentration of a solution in molarity and molality

What is the difference between a solute and a solvent? ESSENTIAL QUESTION What is the difference between a solute and a solvent? What is concentration of the solution?

I can answer all the practice questions given at the end of class OBJECTIVE I can answer all the practice questions given at the end of class

Complete the practice questions at the end of slides in your notes TASK Complete the practice questions at the end of slides in your notes

A solution is a homogeneous mixture A solution is a homogeneous mixture. The components are not chemically combined and retain their original properties. Example: Sugar water – still tastes sweet

Solutions A solution is made up of a solute and solvent. Solute: a dissolved substance can be liquid, solid, gas. Solvent: the most abundant component of a solution, what does the dissolving. Is generally liquid or gas

Water is called the “universal solvent” because it has the ability to dissolve so many substances.

Solutions Recall, aqueous is a solution where water is the solvent. Example: NaCl(aq) Na+ + Cl- That is salt solution t

Solubility  The maximum amount of solute dissolved in a particular solvent at a specific temperature to make a saturated solution Saturated: No more solute can dissolve Unsaturated: More solute can dissolve Supersaturated: More solute is dissolved than theoretically possible

To make a supersaturated solution: Add more solute than solubility allows Heat the solution up Slowly cool it down This is a temporary and unstable state for a solution!

Factors that affect solubility: Temperature: most solid substances have higher solubility as temperature increases All gas solutes have lower solubility as temperature increases Pressure: only affects gas solutes All gas solutes have higher solubility as pressure increases

Solubility Curves For Solid Solutes: For Gas Solutes:

Rate of dissolving: How fast a solute dissolves in a solvent – not to be confused with how much.

Rate can be increased by: Increasing temperature- There is more kinetic energy available to meet the activation energy (energy available for dissolving) Stirring- Increases the interaction between solute and solvent Powdering- Increase surface area of the solute which increases the interaction between solute and solvent

Liquid-Liquid Solutions Miscible: two liquids which uniformly mix together (ex: milk and water) Immiscible: two liquids which will not mix, forms two layers (ex: oil and water) Non-polar + non-polar = miscible Polar + Polar = miscible Non-polar + Polar = immiscible As a general rule: “Like dissolves like”

Concentration Indicates the amount of solute dissolved in a given quantity of solvent. Dilute: a small amount of solute Concentrated: a large amount of solute

Practice Questions 1. Distinguish between a solution in general and an aqueous solution. 2. Identify the solvent and the solute in a solution of table sugar in water. 3.Why is water an excellent solvent for polar compounds but not for nonpolar compounds?

Practice Questions Fill in the best answer for each of the following: A ____________________ solution contains only a small amount of solute. A ____________________ solution contains a large amount of solute. A(n) ______________________ solution contains more solute than it can theoretically hold at that temperature. The ____________________ is the amount of a substance that dissolves in a given quantity of solvent at a particular temperature to produce a saturated solution. A(n) ______________________ solution contains the maximum amount of solute that can be dissolved in that solvent at that temperature.