COMPOUNDS are homogeneous materials with definite composition which may be decomposed into two or more simpler substances by chemical change.

COMPOUNDS are homogeneous materials with definite composition which may be decomposed into two or more simpler substances by chemical change.

ACIDS & BASES

ACIDS are characterized by:

a) Sour tasteb) Turns blue litmus

paper to redc) React with bases to

form salts & waterd) React w/ active

metals to produce hydrogen gas.

e) “burns” your skin: corrosive

f) pH value : 0 to 6.9

BASES (also ALKALI) characterized by:a) Turns red litmus paper

to blueb) Slippery and soapy feelc) Bitter or biting tasted) React with acids to form

salts and watere) Turns fats into soaps

f) pH value : 7.1-14

ELECTROLYSIS is a chemical process by which an electric current is applied into their constituent elements that changes the composition of the materials.

SOLUTIONS are homogeneous mixture that is composed of a solute and a solvent. The new

combination has only one phase.

SUSPENSIONS are heterogeneous mixtures that have the biggest particles.

COLLOIDS are heterogeneous mixture in which one substance is dispersed evenly throughout

another

Classify the following matter : Homogeneous, Heterogeneous,

Compound or Element

Cement

Dust free air

22 karat Gold bracelet

Pure NaCl

Al metal

Dry sugar + flour

Filtered Sea water

Na metal

Brass

Homogeneous mixture

Heterogeneous mixture

Homogeneous mixture

Compound

Element

Heterogeneous mixture

Homogeneous mixture

Element

Homogeneous mixture

DECANTATION is the separation of mixtures with different densities.

CHROMATOGRAPHY is the separation of components in a mixture based on the affinity for the solvent.

What method will you use to separate immiscible liquids? (Oil and water)

It can be separated using a SEPARATING FUNNEL. This apparatus allows the lower, more dense liquid to be drawn off at the bottom, leaving the less dense liquid in the funnel.

An older and less satisfactory technique is the process of DECANTING where the top layer is simply poured off.

Problem: Aquarium B has to be filled with some water samples brought from the coast. However, this sample is suspected to be contaminated with a dissolved solid and a dissolved liquid. If the water is not purified, it cannot be used by the fish.

Task: Obtain a clean sample of water and show the pollutants that were affecting the water.

Questions:What types of mixtures are observed in the aquarium?What is meant by physical means of separation? What is the difference with chemical means?

THE END…..