Topic: Chemistry Aim: Describe the properties and different types of mixtures. Do Now: 1. Take out Density ISA 2. CONTRAST elements and compounds. HW: Mass, Temperature and Density Exam Review Sheet

1. Identify the structure with the greatest density. Support your answer. Bolt because it sank all the way to the bottom. 2. Identify the structure with the smallest density. Support your answer. Ping pong ball because it is floating at the top. 3. Identify the liquid that is the least dense. Support your answer. Lamp oil because it is at the top.

4. Identify the liquid that has the greatest density. Support your answer. Honey because it is at the bottom. 5. Which is least dense: the milk or the rubbing alcohol? Support your answer. Rubbing alcohol because it is above milk.

Which scenario represents a chemical change? Support your answer.

Mixtures Pure substance – made up of just water molecules Mix of dissolved substances such as salt, fluoride, calcium carbonate, magnesium, iron, etc…

2 or more substances PHYSICALLY MIXED together but NOT CHEMICALLY COMBINED Ex: –Soil –cake batter –cereal with milk

–Vinegar –Concrete

For example powdered iron and powdered sulfur mixed together makes a mixture of iron and sulfur. They can be separated from each other without a chemical reaction, in the way that different colored sweets can be picked out from a mixed packet and put into separate piles.

So… what is the main difference between a compound and a mixture? In a compound, substances are CHEMICALLY COMBINE. In a mixture, substances are NOT CHEMICALLY COMBINED. They are PHYSICALLY COMBINED!

ABC Distinguish the element, mixture and compound. Support your answer.

Sugar solution Milk is a combination of water, sugars, proteins, and fats making it a mixture. A sugar solution is a combination of sugar and water.

Vinegar is a combination of acetic acid and water. Jello consists of gelatin and water.

Solutions Mixture that contains small and dissolved particles

Solute: substance dissolved Solvent: substance that does the dissolving Parts of a solution

Identify substances A and B. B A

A soft drink is a solution that contains several dissolved substances in water.

Solubility How well a solute dissolves

Dissolves in another substance –Ex: Salt and sugar dissolve in water Sugar water solution Salt water solution Soluble substance

Sugar water solution CANNOT dissolve in another substance Ex: oil Insoluble substance

Obviously NOT soluble in water!!!!

A lava lamp depends on the globs not being soluble. It also depends on the globs being about the same density as water. It took years to develop the right ingredients to make a lava lamp work.

Factors that affect solubility

1. Temperature: As temp of solvent increases, solubility of the solute increases

2. Particle size: the smaller the size, the greater the solubility powdered sugar sugar granules

3. Stirring: increases solubility

Let’s summarize… 1.Explain what makes up a mixture. 2.Describe the difference between a compound and a mixture. 3.Explain what a solution consists of. 4.Identify the factors that affect solubility.

Review: Which of the following is an example of a mixture of gases? 1.soft drink 2.air 3.oxygen 4.water

In sweetened tea, the sugar is called the 1.solute. 2.solvent. 3.colloid. 4.solution.

Which of the following would help sugar dissolve faster in water? 1.stirring the water 2.decreasing the solubility of sugar 3.using larger particles of sugar 4.decreasing the water temperature

Which statement is true regarding insoluble substances? 1.They can be easily dissolved in a solvent. 2.An example of an insoluble substance is ice tea dissolving in water. 3.Insoluble substances cannot dissolve in a solvent. 4.They can easily dissolve in a solute.

Chemical change Physical changeChemical change

Tarnishing of silver Chemical change Tarnish is silver sulfides that form from sulfur compounds in the air.

Element or compound? 1.NaCl 2.O 3.C 6 H 12 O 6 4.CO 2 5.O 2 Compound Element Molecule Compound