Unit 2: Chemical Reactions

Color

Texture

density

smell

solubility

melting point

state

if no new substance is created a reaction is considered
to be a physical reaction

Combination

Two or more substances to make a lesser number of substances

Decomposition

One substance breaks apart into a fewer amount of substances

Single Displacement

an element and compound react and the element replaces one element in the compound

In order to replace another element in a compound, the element trying to replace it will have to be higher on the activity series of metals in reactivity. The same thing can be said about halogens replacing halogens

Double Displacement

two compounds react to form two different compounds

Substances with ph levels above 7

Reaction with acids or bases

flammability

bleaching ability

corrosion

A reaction that results in 1 or more new
substances is considered a chemical reaction

In a chemical reaction atoms are neither created
nor destroyed, just simply re arranged

Reactions can be shown in 2 ways:

Word Equations:
Sodium + chlorine = sodium chloride

Chemical equations:
2K + Cl2 = 2KCl

Chemical equations need to be balances
to have the same number of molecules on
either side of the equal sign

For example K + Cl2 = KCl
becomes 2K + Cl2 = 2KCl
to match the number of chlorine
atoms in the first part of the
equation(there are two because
Chlorine is diatomic and will always
be found in pairs when not part
of a compound).

One way to tell when a chemical reaction occurs,
is when a precipitate forms. A precipitate is a solid
forms in a liquid. This means the substance is insoluble.

When a substance is insoluble, it makes it easier to predict if substances will react.

Spectator Ions: ions that appear on both sides of of a chemical equation but don't actually do anything.

Substances with ph levels below 7

Acids and bases can be added together to create a substance with a ph closer to 7