types of mixtures chemistry
DESCRIPTION
I designed these slides for a HS Chemistry class for a properties of matter unit. The lecture followed a paper chromatography lab investigating 3 unknown mixtures of FD &C food dyes. Check out the 3 videos within the lecture to reinforce how mixtures can be separated physically and the negative effects of food dyes on human health.TRANSCRIPT
Types of Mixtures
What’s the difference at the molecular level?
Pure substance, homogeneous or heterogeneous mixture?
• Kool-aid• Fruit loops cereal• Sugar crystals (C6H12O6)
• Air (O2 + N2)• Pizza• Tea• Copper wire (Cu)• Trail mix• Cake batter
Homogeneous Mixture• Uniform composition• One phase (part of sample
with uniform composition/properties)
• Small particles, evenly distributed
• Examples: – Salt water solution– Iodine– Vinegar– stainless steel (mixture of
iron, chromium, and nickel)
Parts of a Solution
• A liquid (solvent) with a substance (the solute) dissolved in it
• Particles are atoms, molecules, or ions (very small)
Heterogeneous Mixture• Not evenly mixed• More than 1 phase• Particles not
uniformly distributed, larger
• Easily separated physically
• Examples: salt and pepper, cereal, rocks, bag of assorted candy
Colloid: A heterogeneous mixture of intermediate-sized particles that don’t settle out
Examples: fog, whipped cream, mayo, smoke
Suspension• A heterogeneous mixture with BIG particles that settle
out when left undisturbed• Liquids that need to be “shaken well before using”
• Examples: oil and vinegar dressing, muddy water