Chemical Reactions

SNC2D

Changes

A change in which no new substances are formed is called a ?

Changes

A change in which no new substances are formed is called a physical change.

Changes

A change in which no new substances are formed is called a physical change.

Ex. ice melting

(both ice and water

are H2O)

Changes

Changes that do change the particles (often because the particles are reacting with the particles of another substance) are called chemical changes or chemical reactions.

Changes

Changes that do change the particles (often because the particles are reacting with the particles of another substance) are called chemical changes or chemical reactions.

Changes

Changes that do change the particles (often because the particles are reacting with the particles of another substance) are called chemical changes or chemical reactions.

Ex. Iron reacts with oxygen in the air to create iron (III) oxide (rust).

Signs and Symptoms

Signs that a reaction has occurred include:• Energy produced or absorbed

Signs and Symptoms

Signs that a reaction has occurred include:• Energy produced or absorbed

(light produced, sound produced,

temperature increase

Signs and Symptoms

Signs that a reaction has occurred include:• Energy produced or absorbed

(light produced, sound produced,

temperature increase or decrease)

Signs and Symptoms

Signs that a reaction has occurred include:• Energy produced or absorbed• New product(s) visible

Signs and Symptoms

Signs that a reaction has occurred include:• Energy produced or absorbed• New product(s) visible

(colour change,

Signs and Symptoms

Signs that a reaction has occurred include:• Energy produced or absorbed• New product(s) visible

(colour change, gas produced

Signs and Symptoms

Signs that a reaction has occurred include:• Energy produced or absorbed• New product(s) visible

(colour change, gas produced,

solid precipitate produced)

Equations

Chemical reactions can be represented by either:

• word equations using the names of the chemicals (e.g. carbon dioxide, water)

Equations

Chemical reactions can be represented by either:

• word equations using the names of the chemicals (e.g. carbon dioxide, water)

or• chemical equations using the formulas of the

chemicals (e.g. CO2, H2O)

Equations

The substances that are reacting are called

____?____

Equations

The substances that are reacting are called reactants and are written on the left side of the equation.

Equations

The substances that are reacting are called reactants and are written on the left side of the equation. There may be only one; if there is more than one, they are separated by ?

Equations

The substances that are reacting are called reactants and are written on the left side of the equation. There may be only one; if there is more than one, they are separated by +.

Equations

The substances that are reacting are called reactants and are written on the left side of the equation. There may be only one; if there is more than one, they are separated by +.

Ex.

carbon dioxide + water

CO2 + H2O

Equations

The new substances formed in the reaction are called ___?____

Equations

The new substances formed in the reaction are called products and written on the right side of the equation.

Equations

The new substances formed in the reaction are called products and written on the right side of the equation.

Ex.

oxygen gas + glucose

Equations

The new substances formed in the reaction are called products and written on the right side of the equation.

Ex.

oxygen gas + glucose

O2 + C6H12O6

The two sides of the equation are separated by

___?____

Equations

The two sides of the equation are separated by an arrow (pointing right) that is read as ?

Equations

The two sides of the equation are separated by an arrow (pointing right) that is read as “produces” or “yields.”

Equations

The two sides of the equation are separated by an arrow (pointing right) that is read as “produces” or “yields.”

Ex.

carbon dioxide + water oxygen gas + glucose

CO2 + H2O O2 + C6H12O6

Equations