Pure Substance vs. Mixture Pure Substance: a type of matter with a fixed composition; every sample has exactly the same characteristic, properties, and composition. - Helium & H2O Mixture: matter composed of 2 or more substances that can be separated by physical means; each which retains its own identity and properties - concrete & saltwater solution

Pure Substance vs. Mixture

Pure Substance vs. Mixture fabrics vinegar table salt rocks milk sugar absolute alcohol (ethanol) isopropyl alcohol lemonade air

Pure Substance vs. Mixture A substance that cannot be broken down into a simpler form by ordinary chemical means is called a(n) A. element B. compound C. mixture D. isotope

Can it be chemically decomposed? Matter Flowchart Compound PURE SUBSTANCE Can it be chemically decomposed? no yes Element 6

One type of Pure Substance: Elements- substance made up of atoms that are all alike All one kind of atom 118 different elements H, O, Cu, Fe, He, Ne Based on this definition is H2 an element?

The other type of Pure Substance: Compounds are substances in which the atoms of 2 or more elements are chemically combined in a fixed proportion. Can be broken down by a chemical change Examples: H2O, NaCl, CaCO3

Element vs. Compound

Element vs. Compound aluminum C2H5OH H2O (dihydrogen monoxide) NaCl calcium, Hg sugar (C12H22O11) ammonia (NH3 ) H2

Element or Compound Sucrose- Copper- Hydrochloric acid- Copper(II) chloride- CuCl2 Oxygen- O2 Potassium- K C6H12O6 Compound Cu Element HCl Compound Element or Compound Compound Element Element

Element vs. Compound Carbon cannot be broken down into anything simpler by chemical means, so carbon must be a. a mixture. b. an element. c. a compound.

What does each box represent? Element vs. Compound What does each box represent?

Is the composition uniform? Matter Flowchart MIXTURE Is the composition uniform? no yes Heterogeneous Mixture Homogeneous Mixture (solution) 14

Mixtures matter composed of 2 or more substances that can be separated by physical means. Heterogeneous mixture is a mixture in which different materials remain distinct. “Hetero” means different

Suspensions Suspension – a heterogeneous mixture made up of a liquid and solid particles that settle. Examples: italian salad dressing, river water

Colloids Colloid – a heterogeneous mixture with particles that never settle Examples: milk, paint, fog, smoke

Identifying Colloids One way to identify colloids is by its appearance. You can identify whether a liquid is a colloid by passing a beam of light through it. A light beam is invisible as it passes through a solution, but can be seen as it passes through a colloid.

Identifying Colloids This occurs because the particles in the colloid are large enough to scatter light, but those in a solution are not. The scattering of a light beam as it passes through a colloid is called the Tyndall effect.

Mixtures Homogeneous mixture- a mixture that remains constantly and uniformly mixed and has particles that are so small that they cannot be seen with a microscope “Homo” means same Solution – the same thing as a homogeneous mixture Both will never settle to the bottom of their container Examples: vinegar, cola, apple juice

Alloys Alloy- homogeneous mixture composed of 2 or more metal elements Examples: * Steel – Fe , C, Cr, Ni * Brass – Cu & Zn * 14K, 10K, 18K Gold

Homogeneous or Heterogeneous Milk- Sugar water- Trail mix- Salt water solution- Steel- Heterogeneous Homogeneous Homogeneous or Heterogeneous Heterogeneous Homogeneous Homogeneous

Day 2

Can it be physically separated? Matter Flowchart MATTER yes no Can it be physically separated? Is the composition uniform? no yes Can it be chemically decomposed? no yes 25

Can it be physically separated? Matter Flowchart MATTER yes no Can it be physically separated? MIXTURE PURE SUBSTANCE Is the composition uniform? no yes Can it be chemically decomposed? no yes Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element

Element, Compound, Heterogeneous, or Homogeneous Titanium- Copper(II) sulfate- Cheeseburger- Calcium chloride - Lithium nitrate solution- Calcium- Acetone- Brass- Element Compound Hetero Mixture Compound Element, Compound, Heterogeneous, or Homogeneous Homo Mixture Element Homo mixture Homo mixture-alloy

Element, Compound, Heterogeneous, or Homogeneous Sodium bicarbonate- Kool-Aid- 10K gold- Helium gas- Sand, salt, and iron- Sand- Compound Homogeneous mixture Homo mixture- alloy Element Element, Compound, Heterogeneous, or Homogeneous Hetero mixture Compound

Separation Techniques Filtration-physical operation which is used for the separation of solids from fluids Separation Techniques

Distillation

Fractional Distillation the separation of a mixture into its component parts, or fractions, using their boiling point and heating them to different temperatures Fractional Distillation

techniques for the separation of mixtures techniques for the separation of mixtures. The various constituents of the mixture travel at different speeds, causing them to separate. Chromatography