Chemical Reactions Quiz #1

The starting materials in a chemical reaction are referred to as

• Products

• Reactants

• Subscripts

• Coefficients

The symbolic representation of a chemical reaction is a

• Chemical Symbol

• Chemical Formula

• Electron Configuration

• Chemical Equation

The Law of Conservation of Mass states

• that matter exists in all states and reacts the same

• that matter can only be changed into new substances by introducing a catalyst

• that matter exists in the same state throughout any chemical change

• that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants

Balance this equation:

Cl₂ + KI → KCl + I₂

• Cl₂ + KI → KCl + 2 I₂

• 2 Cl₂ + KI → KCl₂ + I₂

• Cl₂ + 2 KI → 2 KCl + I₂

Balance this equation:

H₂ + N₂ → NH₃

• H₂ + 4N₂ → NH₃

• H₂ + 3N₂ → 2NH₃

• 3H₂ + N₂ → 2NH₃

• 2H₂ + 2N₂ → 2NH₃

A chemical reaction has occurred if

• there is a precipitate.

• there is a color change.

• there is a temperature change.

• All of these answers are evidence.

3Ca + 2AlCl₃ → 3CaCl₂ + 2Al

• Synthesis

• Decomposition

• Single replacement

• Double replacement

What is a coefficient?

• The small number on the right of the chemical symbol.
• The large number to the left of a formula.

Classify the following:

Al(OH)₃ → Al₂O₃ + H₂O

• Decomposition

• Combustion

• Synthesis

• Single Replacement

What is the definition of a chemical change?

• any change that results in the formation of new chemical substances.

• any change that can not be undone

• any change that destroys or creates new matter

• changes affecting the form of a chemical substance, but not its chemical composition.