Chemical Reaction Basics

Chemical Reaction Basics

Multiple Choice

What is a synthesis reaction?

• When a complex substance breaks down into new and simpler substances

• When there is one substance replacing another substance

• When simpler substances combine together and react to form a new and complex substance

• When two substances are switched after a chemical reaction occurs

Multiple Choice

What is a decomposition reaction?

• When a complex substance breaks down into new and simpler substances

• When there is one substance replacing another substance

• When simpler substances combine together and react to form a new and complex substance

• When two substances are switched after a chemical reaction occurs

Fill in the Blanks

Multiple Choice

What type of reaction is this?

• a synthesis reaction

• a decomposition reaction

• a single replacement reaction

• a double replacement reaction

• a combustion reaction

Match

Match the reaction type to its description.

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

The process of combining two or more substances to form a new compound.

The breakdown of a compound into simpler substances.

A reaction where one element replaces another in a compound.

A reaction involving the exchange of ions between two compounds.

• The process of combining two or more substances to form a new compound.

• The breakdown of a compound into simpler substances.

• A reaction where one element replaces another in a compound.

• A reaction involving the exchange of ions between two compounds.

Molar Mass

Review from Yesterday!

What is a mole?

A mole is simply a unit of measurement, like a dozen, or a bushel, or a boatload.

Multiple Choice

What is Avogadro's Number?

• 6.0 x10^23

• 6.0x10^24

• 1023 x 10^6

• 8675309

Avogadro's Number

A mole of something means 6.02x10²³ of that something.

So a mole of pick up trucks is 6.02x10²³ pick up trucks

Molar Mass

Some text here about the topic of discussion

​Mass of 1 mole of substance.

Units: g/mole

Tabulate all elements

Count number of atoms

Find Atomic Mass of each atom from Periodic Table

Multiply the number of atoms by Atomic Mass

Add all the individual numbers to find Molar Mass​

Open Ended

What is the molar mass of Sodium Chloride (NaCl)?

Open Ended

What is the molar mass of Carbon Dioxide (CO₂) ?

Coefficient of
moles given

Coefficient of
moles unknown

Mole to Mole

Molar Ratio

The coefficients in a balanced chemical
equation tell us the mole ratios of the

reactants and products.

Whichever unit you start with will be the same
unit on the bottom of the first "train track"
Remember when mole on top of mole you
MUST look at the coefficients in the equation

2 : 1 : 2

# moles given

= moles
unknown

Formula for Mole to Mole Stoichiometry

Multiple Choice

Use the balanced equation to answer the following question.

2 FeCl₃ + MgO --> Fe₂O₃ + 3 MgCl₂

How many moles of iron chloride (FeCl₃) will be produced from 5.50 moles of magnesium oxide (MgO)?

• 5.50 mol FeCl₃

• 11.0 mol FeCl₃

• 2.25 mol FeCl₃

• 3.67 mol FeCl₃

Whatever unit you start with, must go on the bottom.

Mole & Mass

Coefficient of
Moles Given

Coefficient of
Moles Unknown

= Mass Unknown

1 Mole Unknown

Molar Mass (PT)
of Unknown (g)

Molar Mass (PT)

Given (g)

Coefficient of
Moles Unknown

= Moles
Unknown (mol)

1 Mole Given

Coefficient of
Moles Given

The hardest part of these types of problems is stopping. Before

beginning these calculations, please check the starting and ending

units to ensure you get the correct answer.

​# Moles Given

Grams Given

Multiple Choice

Use the balanced equation to answer the following question.

4 NH₃ + 5 O₂ → 4 NO + 6 H₂O

How many grams of nitrogen monoxide (NO) will be produced from 2.50 moles of oxygen (O₂)?

Molar Mass NO: 30.01 g/mol Molar Mass O₂: 32.00 g/mol

• 60.0 g NO

• 64,.0 g NO

• 2.00 g NO

• 75.0 g NO

Mass to Mass
Stoichiometry

When completing these calculations, please be sure that your units cancel.

This means whatever unit you start with MUST match the following bottom unit.

The words or numbers in color represent something other than 1.

Coefficient of
Moles Given

Coefficient of
Moles Unknown

= Mass Unknown (g)

1 Mole Unknown

Molar Mass (PT)
of Unknown (g)

Molar Mass (PT)

Given (g)

1 Mole Given

# Mass Given

Multiple Choice

Use the balanced equation to answer the following question.

3 Ca(OH)₂ + 2 H₃PO₄ --> Ca₃(PO₄)₂ + 6 H₂O

Molar mass of Ca(OH)₂: 74.10 g/mol Molar mass of Ca₃(PO₄)₂: 310.18 g/mol

How many grams of calcium hydroxide (Ca(OH)₂) are required to produce 65.1 grams of calcium phosphate (Ca₃(PO₄)₂)?

• 0.21 g Ca(OH)₂

• 46.7 g Ca(OH)₂

• 23.3 g Ca(OH)₂

• 272.5 g Ca(OH)₂