Unit 12: Properties of Solutions
Reading
BJU Chemistry: Ch. 12 "Solutions"
AP Classroom: Unit 6 "Thermodynamics" (we need to move ahead to Thermo to stay on track)
AP Princeton Review: Unit 6
Topics
Labs
Some virtual labs which pertain to the topic
Research assignment
Gold Recovery from Scrap Electronics. Instructions below.
BJU Chemistry: Ch. 12 "Solutions"
AP Classroom: Unit 6 "Thermodynamics" (we need to move ahead to Thermo to stay on track)
AP Princeton Review: Unit 6
Topics
- Types of solutions and their properties
- Solvents and solutes, solubility concepts
- Molarity and percent concentration
Labs
- Environmental Science lab (Treating wastewater using chemistry)
- Crystallization lab
Some virtual labs which pertain to the topic
- Concentration weblab - handout below
- Molarity weblab
- Salts and Solubility weblab
- Sugar and Salt Solutions weblab
Research assignment
Gold Recovery from Scrap Electronics. Instructions below.
Quick Summary
- A solution is a homogenous mixture of two or more substances. The most abundant component is called the solvent, and the less abundant components are called solutes.
- An easy example is seawater.... a mixture of 3.5% salts (the solutes) dissolved in water (the solvent)
- A more subtle example is air.... a mixture of 22% oxygen and other gases (the solutes) dissolved in nitrogen gas (the solvent)
Molarity concept
Parts per million (PPM)
Colloids
- Molarity (M) is one way to measure the concentration of a solution. Molarity is defined as moles of solute per liter of solution (mols/L of solution). A 6M solution of HCl contains 6 moles of hydrogen chloride in 1 liter of aqueous solution. We would then refer to it as "1 liter of 6-molar hydrochloric acid".
Parts per million (PPM)
- We often use "parts per million" or "ppm" to describe concentration, especially in aqueous solutions.
- 1 ppm = 1 mg/L
- For example, tap water in So. California contains about 500ppm dissolved solids. That means there are 500mg of various salts contained in 1L of tap water.
Colloids
- Colloidal dispersions are a very important class of mixtures
- The easiest way to imagine a colloidal mixture is to picture a beaker of water with fine silt stirred in. The silt particles aren't really "dissolved", but they are so small and light that they never settle to the bottom.
- Colloids aren't mixtures or suspensions. Mixtures are homogenous, and suspensions eventually settle out. Colloids aren't either.
- Examples: fog, clouds, mist, paint, smoke, blood, polluted water with fine particulate matter
Environmental Science lab (Wastewater treatment using chemistry)
12._environmental_science_lab_handout_-_showing_molarity_calcs_5_wastewater_samples_photo.docx |
12._environmental_science_lab_handout_-_solns_mixtures_charts.docx |
Concentration weblab
12._concentration_weblab__rev_2024_.docx |
Homework
Handouts below. Other homework on Canvas.
Handouts below. Other homework on Canvas.
10._know_your_ions_part_2..docx |
Gold Recovery assignment
gold_recover_assignment_rev_2021.docx |