Solution and Suspension PPT - part1

Solutions and Suspensions
part 1 – Matter, Solutions

Kalam Kudus Christian School

Chemistry Checkpoint 2

Mr. Markus

                          

Pure Substance

• A type of matter in which all particles are of the same chemical composition (element, compound)

• Au (pure gold)

• H2O

• NaCl

• Sugar (C6H12O6)

• Ar

• Which of the previous examples is a compound?  an element?

• Why is salt water not a pure substance?

Mixtures

• Two or more pure substances physically mixed together.

• Cannot be represented by a chemical formula.

• Salt water

• Sand and rocks

• Air

Heterogeneous Mixture

• A mixture where substances are not evenly distributed (non uniform)

• oil and vinegar salad dressing

• vegetable soup

• sand and sugar

• soil

• granite

Homogeneous Mixture (Solution)

• A mixture where all components are evenly distributed (uniform).

• “same throughout”

• salt water

• gasoline

• syrup

• air

Practice

• Identify each of the following as:

• pure substance/mixture

• element/compound

Definition of Solutions

• A solution is a homogeneous mixture in which one substance is dissolved in another substance

• The solute is(are) the substance(s) present in the lesser amount(s), dissolved by the solvent

• The solvent is the substance present in the larger amount, does the dissolving/dissolves the solute

Solution

• Formed when one substance is dissolved by another.

• In order to be dissolved, a substance must be soluble.

• A homogeneous mixture.

• Particles are evenly distributed.

• Parts cannot be separated by filtering.

• Solvent—does the dissolving

• Solute—dissolved by the solvent

Solution Practice

• Identify the solute and solvent in each of the following:

• Salt water

• Iced tea

• Coca-cola coke

• Paint/paint thinner

• Nail polish/acetone

• Ethanol

Types of Solutions

• Solid dissolved in a liquid.

• Salt water

• Gas dissolved in a liquid

• Coca-cola

• Two solids

• Metal alloys: brass = copper + zinc

• Two gases

• Air: nitrogen (78% vol), oxygen (21% vol), argon (1% vol), carbon dioxide (0.03% vol).

• In solutions of 2 solids or 2 gases, the solvent is the component present in largest quantity. 

IONIC COMPOUNDS
Compounds in Aqueous Solution

Many reactions involve ionic compounds, especially reactions in water — aqueous solutions.

K+(aq)  +  MnO4-(aq)

KMnO4 in water

Aqueous Solutions

How do we know ions are present in aqueous solutions?

They are called ELECTROLYTES

HCl, MgCl2, and NaCl are strong electrolytes. They dissociate completely (or nearly so) into ions.

Aqueous Solutions

Some compounds dissolve in water but do not conduct electricity.  They are called nonelectrolytes.

Examples include:

sugar

ethanol

ethylene glycol

nonelectrolyte

weak electrolyte

strong electrolyte

Electrolytes in the Body

 

Make your own

50-70 g sugar One liter of warm water Pinch of salt 200ml of sugar free fruit squash Mix, cool and drink

• Carry messages to and from the brain as electrical signals

• Maintain cellular function with the correct concentrations electrolytes