Matter

MATTER

• Occupies space• Have mass

Almost everything in the universe is matter.

Can you give examples of what are not matters?

Author: Mr Lam

Matter

Can it be separated by

physical means?

Is the compositi

on uniform?

Can it be decomposed by

ordinary chemical means?

Elements

no

Mixtures

yes

Homogeneous

mixtures (Solution)

yes

Compounds

yes

Heterogeneous mixtures

no

Pure Substances

no

Homogeneous Vs heterogeneous

When you take (sample) two spoons of the mixture out from the bulk, if the compositions of the mixtures in each spoon are the same, then we call it, homogeneous, e.g. Milk

On the other hand if the compositions in each spoon is different from each other, we call it heterogeneous, e.g. Noodle soap.

Give three examples in each category

Homogeneous mixtures

Heterogeneous mixtures

Compounds Elements

1. 1. 1. 1.

2. 2. 2. 2.

3. 3. 3. 3.

Homogeneous Mixtures

A homogeneous mixture also commonly named as a “Solution”.

Example:

Salt = Solute Water = SolventSalty water = Solution

Note: All gases mixture must be homogeneous. e.g. air

Heterogeneous mixtures

Solid/solid e.g. rice with m&m chocolate

Liquid/liquid e.g. French salad dressing, metal with metal oxide (smelting), milk

Solid /liquid e.g. muddy water

Liquid/gas e.g. milk/air =ice-cream

Solid/gas e.g. saw dust in air

Liquid/solid heterogeneous mixtures

If the mixture is very easy to sediment (settle), the process is called sedimentation

If the mixture takes some time to sediment, the mixture is called suspension

If the mixture does not sediment even after a very long time, the mixture is called colloid.

Note: liquid/liquid mixture with very fine droplets, we also call the mixture as emulsion.

Miscible/immiscible

If two liquids can dissolve into each other, we say these two liquids are miscible.

For example, vinegar and water, alcohol and water

If two liquids cannot not dissolved into each other, we say these two liquids are immiscible, e.g. water and oil.

The words Miscible/Immiscible are very similar to dissoluble and indissoluble. But miscible/immiscible describes specifically for liquids.

Difference between mixtures and compounds

Mixture has the average properties of its components. e.g. salty water is still tasted salty, iron needles in a haystack, still attracted by magnets

Compound has new properties. e.g. ashes from burning paper in air, vinegar & baking soda becomes carbon dioxide and another solution with no acidic property

Compounds and Elements

Different compounds are different combinations of different elements

The properties of compounds can vary a lot when the composition of the elements only varied a little bit.

We will discuss more about element and atom next year.

Separation techniques

Magnetic separation Decantation Flotation Centrifugation Filtration Separation Funneling Evaporation Crystallization Distillation Chromatography And many more….

Same mixture can be separated by different methods.

Sometimes a few of these techniques are needed to extract the desired substances.

Decantation

Application of decantation

Flotation

Application of Flotation

Flotation process, in mineral treatment and mining, process for concentrating the metal-bearing mineral in an ore.

Crude ore is ground to a fine powder and mixed with water, frothing reagents, and collecting reagents.

When air is blown through the mixture, mineral particles cling to the bubbles, which rise to form a froth on the surface.

The waste material (gangue) settles to the bottom. The froth is skimmed off, and the water and chemicals are distilled or otherwise removed, leaving a clean concentrate.

The process, also called the froth-flotation process, is used for a number of minerals, especially silver.

Centrifugation

Application of Centrifugation

Separation of blood Uranium enrichment (see link)

Filtration

Increase the yield by rinsing

The proper way to hold a beaker with a glass rod

Separation Funneling

Evaporation

Crystallization

Distillation

Distillation is good for separating liquids with different boiling points.

The lower boiling point liquid collected at the conical flask

Note: the water in and water out positions of the condenser.

Chromatography