Substances, Compounds & Mixtures

How everything is put together.

Classification of Matter

Elements

 Matter that has the same composition and properties throughout is called an_____________.

• When different elements combine, other substances are formed.

Picture from http://www.ilpi.com/msds/ref/gifs/statesofmatter.gif

Elements

 Contains only one particle  Can exist in 3 states of matter _________________ _________________

Compounds

 Ban DHMO?

 DHMO is dihydrogen monoxide.

 Evaluate the following link and decide if this potentially dangerous chemical should be prohibited.

 www.dhmo.org

Compounds

 A

compound

is a substance whose smallest unit is made up of atoms of more than one element _______________ together.

• Compounds often have properties that are ___________ from the elements that make them up. • Examples:_______________ _______________________

Compounds

General Rules:

- Only

write

the name of the

metallic element _______________

- Write the

number of atoms

of any element in the compound in ________________

(applies to only 2 or more atoms)

“

_________

” will always be written at the

end

of the __________________

element

Compound Properties

Compounds are formed by ________________________________. However, they

do not have

the properties as them.

Because of chemical bonds, compounds cannot be broken down by ____________ means. They can only be broken down by __________________________________.

How do we name compounds? Rule 1 •

Sodium chloride

— made up of the elements sodium and chlorine •

Zinc oxide

— made up of the elements zinc and oxygen •

Carbon dioxide

— made up of the elements carbon and oxygen

Fixed Composition of Compounds For example, water (H

2

O) is a compound made only by joining together two atoms of hydrogen to one atom of oxygen. That is, the ratio of hydrogen atoms to oxygen atoms in water is always 2 : 1.

Chemical Formula of a Compound A compound can be represented by a chemical formula. The chemical formula states • • Types of atoms: hydrogen, oxygen Ratio of H to O = 2:1

How do we write chemical formula?

Rule 1 For many compounds that contain both metallic and non-metallic elements, _____________________________________ _____________________________________ _____________________________________ • calcium oxide (CaO) • sodium chloride (NaCl) • magnesium carbonate (MgCO 3 )

How do we write chemical formula?

Rule 2 • water (H 2 O, not H2O or 2HO) • magnesium carbonate (MgCO 3 , not MgCO 3 or MgC 3 O)

How do we write chemical formula?

Rule 3 • water (H 2 O, not H 2 O 1 ) • calcium oxide (CaO, not Ca 1 O 1 )

How do we write chemical formula?

Rule 4 • water (H 2 O, not OH 2 ) • carbon dioxide (CO 2 , not O 2 C) • nitric acid (HNO 3 , not O 3 NH)

 

Let’s try it…

 How many atoms of each element are there in the compound?

Sulfuric Acid H 2 SO 4

 __ Hydrogen   __ Sulfur __ Oxygen

Hydrogen Peroxide H 2 O 2

 __ Hydrogen  __ Oxygen

And some more formulas…



Carbon Dioxide CO 2

 __ Carbon  __ Oxygen 

Carbon Monoxide CO

  __ Carbon __ Oxygen 

Calcium Carbonate CaCO 3

 __ Calcium  __ Carbon  __ Oxygen



Compound Review

A pure compound has the same elements and the same amount of elements all of the time

 Elements are chemically combined  Compound properties are different from the properties of the elements  They cannot be separated physically  Physical properties such as boiling point or melting point of pure substances are do not change

Mixtures

 A mixture is a combination of _________________ _________________ where there is

no

chemical combination or reaction.

Mixtures combine physically in _______________ _______________ ______________. They just mix.

_______________ _______________ can be combined to create a mixture.

Mixture Types



MIXTURES MAY BE ______________ OR ______________

Homogeneous Mixtures

 

Homogeneous Mixtures:

The prefix: "homo"- indicates ______________  Have the same uniform appearance and composition throughout

Solutions



SOLUTIONS-

are ____________ mixtures

What is a solution?

 A solution is a mixture of two or more substances.

 At least two substances must be mixed in order to have a solution

A solution has two parts

 The substance in the smallest amount and the one that ________ is called the ____________  The substance in the larger amount is called the ___________ - it does the dissolving  In most common instances _______ is the solvent

Examples of solutions

 _________  _________  _________  _________

Heterogeneous Mixtures

:  The prefix: "hetero"- indicates _____________  A heterogeneous mixture consists of visibly different substances or phases  Two or more parts can be seen

Examples:

 _____________  _____________  _____________  _____________

Suspensions

 A ___________ is a heterogeneous mixture of large particles  These particles are visible and will settle out on standing  Examples of suspensions are:

Classification of Matter

Compounds vs Mixtures

Compounds Mixtures