Unit 8: Chemical Reactions Honors

Reactants

In a chemical equation, the (reactants/products) come before the arrow.

Products

In a chemical equation, the (reactants/products) come after the arrow.

Exothermic

In an _______________________ reaction, energy is released as a product.

Endothermic

In an ______________________ reaction, energy is absorbed as a reactant.

What are the 7 diatomic molecules?

H, O, N, F, Cl, Br, I

The Law of _________________________________________________ states that matter cannot be created or destroyed.

Conservation of matter

balanced equation

An equation that has equal numbers of each type of atom on each side.

subscript

The __________________ (small number to the right of a symbol) multiplies the element or polyatomic ion it is attached to

coefficient

The _______________________________ (big number in front of a compound) multiplies the whole compound it is next to

Never change the _______________ in a chemical equation because it changes the substance. To balance an equation, only change the _________________.

subscripts, coefficients

What do you do if you end up with an odd number on one side of the equation and an even number on the other side?

Multiply all coefficients by two and then balance

A _____________________________ reaction occurs when an organic compound reacts with oxygen to form carbon dioxide and water.

Combustion

A _____________________ reaction occurs when two or more substances react to form a new compound

Synthesis

A _____________________ reaction occurs when a single compound breaks down to form 2 or more simpler compounds

Decomposition

A ____________________ reaction occurs when a single element reacts with a compound and takes the place of one of the elements in the compound

Single Displacement

A ___________________ reaction takes place when a molecular compound forms from the apparent exchange of atoms or ions between two compounds

Double Displacement

Balance and classify the following equation:

_____HBr + _____O₂ → ____Br₂ + ____H₂O

4HBr + O₂ → 2Br₂ + 2H₂O, single displacement

In a chemical reaction, the products have different ______________________ than the reactants

chemical properties

What is the formula for nitrogen gas?

N₂

The total mass of reactants in a chemical reaction will always be ___________________ the total mass of products, according to the law of conservation of mass.

equal to

What type of reaction follows this general format? AB → A + B

Decomposition

What type of reaction follows this general format? A + B → AB

Synthesis

What type of reaction follows this general format? AB + C → AC + B

Single Displacement

What type of reaction follows this general format?

AB + CD → AD + CB

Double Displacement

What are the products of a combustion reaction?

CO₂ and H₂O

When metal carbonates decompose, they produce

metal oxides and CO₂

When metal hydroxides decompose, they produce

metal oxides and H₂O

Balance and classify the following equation:

___Mg + ___Fe₂O₃ → ___Fe + ___MgO

3Mg + Fe₂O₃ → 2Fe + 3MgO, single displacement

Balance and classify the following equation:

___C₆H₆ + ___O₂ →___CO₂ + ___H₂O

2C₆H₆ + 15O₂ → 12CO₂ + 6H₂O, combustion

What product forms when lithium reacts with oxygen? What type of reaction is this?

Li₂O, synthesis

What products form when BaCl₂ reacts with Na₂SO₄? What type of reaction is this?

BaSO₄ and NaCl, double displacement

What products form when hexene (C₆H₁₆) reacts with oxygen?

Carbon dioxide and water

What products form when MgCl₂ decomposes?

Mg and Cl₂

What products form when gold reacts with magnesium chloride?

None, no reaction occurs.

What products form when potassium reacts with hydrochloric acid?

KCl and H₂

sum of oxidation numbers of a compound

zero

sum of oxidation numbers of an ion

equals the charge of the ion

oxidation

half reaction where electrons are lost

reduction

half reaction where electrons are gained

oxidation-reduction reaction

redox reaction

oil rig

oxidation is loss-reduction is gain

oxidation number of a free element

0

oxidation number of a monatomic ion

charge of the ion

oxidation number of group 1 elements

\+1

oxidation number of group 2 elements

\+2

oxidation number of group 13 metals

\+3

oxidation number of H

\+1 unless bonded to a metal, then = -1

oxidation number of O

\-2 unless bonded to F then = +2 or in peroxide then = -1

Which element is oxidized? 2Na + Cl₂ → 2NaCl

Cl

Which element is oxidized? 2Na + Cl₂ → 2NaCl

Na

What are the four steps for predicting the products of a reaction?

1\. Write formulas for the reactants

2\. Determine what kind of reaction it is

3\. Write formulas for the products based on type of reaction

4\. Balance the equation