Chemistry Rev 012312 A singularity expanded rapidly to form the beginnings of our universe. The...

Chemistry

Rev 012312

A singularity expanded rapidly to form the beginnings of our universe. The universe began to cool and the

wavelengths of light became too long for us to see. And so the universe

appeared black.

Soon, particles began to form.

Quarks and electrons, and eventually protons and neutrons.

Eventually glowing clouds of hydrogen gas form, along with young stars.

Eventually glowing clouds of hydrogen gas form, along with young stars.

You are here

Galaxies form

A small yellow star in the corner of the Milky Way Galaxy develops a following of rocky planets and gas giants.

One planet in particular exhibits the potential for life.

It has water and eventually develops oxygen

Earth is in the Goldilocks spot.

Everything is “just right” for …Everything is “just right” for …

Chemistry

Life abounds

Scientists have found complex chemical compounds throughout the universe.

Chemistry

everything in the universe

is all about

Everything in the universe

MatterEnergy

is either

or

Matter

Energyand

are equivalent

E=mc2

MatterEnergyE=mc2

MatterEnergyE=mc2

Chemistry

MatterIs anything that

has mass, and takes up space.

Matter

Physical Properties

Chemical Properties

Chemical Properties

… are all about chemical changes

2 H2(g) + O2(g) 2 H2O(g)

Chemical Properties2 H2(g) + O2(g) 2 H2O(g)

Hydrogen and oxygen are stored in the external fuel tank.They react to produce water vapor, which exits at the nozzles.

Chemical Properties3Al(s) + 3NH4ClO4(s)

In the solid rocket boosters (SRB’s) aluminum metal reacts with ammonium chlorate.

Al2O3(s) + AlCl3(s) + 3NO(g) + 6H2O(g)

Chemical Properties3Al(s) + 3NH4ClO4(s)

And of course, heat is released.

Al2O3(s) + AlCl3(s) + 3NO(g) + 6H2O(g)

Most chemical changes are accompanied by energy changes.

Chemical Properties

Flammability

… are those that influence the way substances react to form new substances.

Acidity

Reactivity

Physical Properties… are things we can measure….

mathematically

Physical PropertiesMass

VolumeDensity

Melting pointBoiling point

Physical properties are things we can quantify.

V

mD

ColorOdor

HardnessMalleability

Ductility

Specific heat capacity

Physical Properties

Conductivity

Solubility

There is a fine line between chemical changes and physical properties.

Many physical properties involve chemical changes.

The value of the solubility of a salt is a physical property, but the process of dissolving is a chemical change.

Matter… has three physical states

solidliquid

gas

Changes in the physical state involve subtle chemical changes.

solidliquid

gas

Energy is absorbed or released as intermolecular bonds are broken or formed.

solidliquid

gas

The degree to which the molecules interact determines if a substance is a solid, liquid or gas.

solidliquid

gas

In a solid, the molecules are close together in an orderly arrangement, with very high intermolecular attraction.

solidliquid

gas

In a liquid the molecules are farther apart but move about in a random fashion, with a high degree of attraction.

solidliquid

gas

In a gas, the molecules are much farther apart, move randomly, with very little attraction between molecules.

solidliquid

gas

Mattercan be classified as either a

mixture

pure substanceor

pure substanceHas definite composition.

Compoundsor

Elements

An element is one of the basic building blocks of nature.

There are 88 to 90 naturally occurring elements.

An element is one of the basic building blocks of nature.

Elements are distinguished by the different numbers of

protons in their nuclei.

Elements are represented by symbols.

HN

OC

NeAl

FeU

Compounds are represented by groups of symbols.

NaCl H2O

C12H22O11

Fe2(SO4)3

A compound is the chemical combination of

two or more atoms.

Compounds have a definite composition.

Water is the same everywhere in the universe.

Water is always H2O.

There are no water molecules anywhere with a different composition.

Water is H2O. Hydrogen peroxide is H2O2 and OH is the hydroxyl radical.

They contain the same elements, but in different ratios.

Water, hydrogen peroxide and the hydroxyl radical all have different chemical and physical properties.

Water is H2O. Hydrogen peroxide is H2O2 and OH is the hydroxyl radical.

Demo: To two beakers each containing a solution of KMnO4, add equal amounts of water to one and H2O2 to the other.

To the solution of KMnO4 and water, add H2SO4 and then add H2O2, preferably on a magnetic stirrer.

What are some other elements that you are familiar with?

Do you know any more formulas for

chemical compounds?

mixtureComposed of two or more pure substances with no definite composition.

Describe something that is a mixture.

mixtureheterogeneous

homogeneous

See the individual components

Appears to be uniform

A solution is a homogeneous mixture.

A solution contains a solute and a solvent.

The solute is what is dissolved …. sugar.

The solvent is what does the dissolving - …..water.

Sugar and water are both pure substances.

C12H22O11 and H2O

They each have their own definite composition.

Sugar and water are both pure substances.

C12H22O11 and H2O

They can be mixed in almost any proportion to make a solution.

A solution is a homogeneous mixture that is uniform throughout.

Once dissolved, you won’t be able to see the sugar in the solution.

But unlike a compound, the mixture can be easily separated back into water and sugar.

Suggest a method for doing that.

But the water and sugar themselves cannot be separated into the elements by physical means.

To do that requires…

Chemistry

Let’s review

How are matter and energy related?

Matter

Energyand

are equivalent

E=mc2

How do we describe matter?

MatterIs anything that

has mass, and takes up space.

What does matter consist of?

MatterConsists of atoms

which combine to form molecules.

What are some properties of mater?

Matter

Physical Properties

Chemical Properties

Chemical Properties… are those that influence the way substances react to form new substances.

Flammability Acidity

Reactivity

Physical Properties… are things we can measure….

mathematically

What are some physical properties?

Physical PropertiesMass

VolumeDensity

Melting pointBoiling point

Phase changes are subtle chemical changes.

V

mD

ColorOdor

HardnessMalleability

Ductility

Specific heat capacity

Physical Properties

Conductivity

Solubility

What are pure substances?

pure substanceSomething that cannot be broken into simpler substances by physical means.

Compoundsor

Elements

What is a mixture?

mixtureComposed of two or more pure substances with no definite composition.

mixtureheterogeneous

homogeneous

See the individual components

Appears to be uniform

A solution is a homogeneous mixture.

What is a solution?

A solution contains a solute and a solvent.

The solute is what is dissolved - sugar.

The solvent is what does the dissolving - water.

A solution is a homogeneous mixture that is uniform throughout.

Once dissolved, you won’t be able to see the sugar in the solution.

What is the study of matter and energy and the connection between the two?

Chemistry

Copyright 2012Mike Jones

Pisgah High SchoolCanton NC 28721All rights reserved.