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)
Topics
Lots of lab possibilities (we'll decide when we get here)
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)
Topics
- Types of solutions and their properties
- Solvents and solutes, solubility concepts
- Molarity and percent concentration
Lots of lab possibilities (we'll decide when we get here)
- Wastewater Treatment lab
- 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
Wastewater Treatment lab
| 11._wastewater_lab_report_-_5_samples_molarity_calcs_photo |
| solutions_handout_with_3_tables.docx |
| chart-_solubility_vs_temp_for_numerous_salts.jpg |
| chart-_solubility_vs_ph_for_6_heavy_metals__from_epa_.png |
"Concentration" weblab
| phet_-_concentration_weblab__revised_2020_.docx |
Homework
Gold Recovery research assignment
| gold_recover_assignment_rev_2021.docx |
