Chapter 4

Question 1

Unit of measurement for mass of an atom

Answer 1

1 amu = 1.66 x 10^-24

Question 2

Where can you find the atomic weight

Answer 2

number on periodic table

Question 3

Whats the amu of an element on the periodic table?

Answer 3

the number listed on periodic table

Question 4

Whats the number for a mole of atoms?

Answer 4

6.022 x 10^23

Question 5

Another name for a ‘mole’

Answer 5

Avogadro’s number

Question 6

Definition of a mole?

Answer 6

Counting unit

Question 7

How to convert grams to moles?

Answer 7

Divide grams by moler mass

Question 8

Formula Unit

Answer 8

the smallest collection of atoms that provide two important pieces of information

• Identity of the atoms
• The relative # of each type of atom

Question 9

Hydrate?

Answer 9

compounds containing one or more water molecules as an integral part of their structure

Question 10

Formula weight

Answer 10

sum of the atomic weights of all atoms in the compound as represented by its correct formula (expressed in amu)

Question 11

How to find amu of a compound

Answer 11

add amu of all elements in compound up

Question 12

what is the atomic weight also known as?

Answer 12

AMU

Question 13

Formula weight is also known as?

Answer 13

Molar Mass

Question 14

What is the molar mass of (NH4)sub3POsub4

Answer 14

149.10g/mol

Question 15

What is the ‘molar mass’?

Answer 15

It’s the mass in grams of 1 mole of atoms

Question 16

What is molar mass of carbon?

Answer 16

12.01 g/mol C

Question 17

Chemical Equation?

Answer 17

shorthand notation of a chemical reaction

Question 18

Reactants

Answer 18

(starting Materials) - the substances that undergo change in the reaction

Question 19

Products

Answer 19

Substances produced by the reaction

Question 20

5 Features of a Chemical Equation?

Answer 20

1. Identity of products and reactants must be specified using chemical symbols
2. Reactants are written to the left of the reaction arrow and products are written to the right
3. Physical states of reactants and products may be shown in parentheses
4. Symbol ^ over the reaction arrow means that energy is necessary for the reaction to occur

Question 21

Evidence of a reaction occurring?

Answer 21

• Release of a gas
• Formation of a solid (precipitate)
• Heat is produced or absorbed
• Color changes

Question 22

Subtle indications of a reaction?

Answer 22

• Heat or Light is absorbed or emitted
• Changes in the way the substances behave in an electrical or magnetic field before and after reaction
• Changes in electrical properties

Question 23

Patterns of chemical reactions

Answer 23

• combination
• decomposition
• single-replacement
• double-replacement

Question 24

Types of combination Reactions

Answer 24

1. Combination of a metal and a nonmetal to form a salt
2. Combination of hydrogen and chlorine molecules to produce hydrogen chloride
3. Formation of water from hydrogen and oxygen molecules
4. Reaction of magnesium oxide and carbon dioxide to produce magnesium carbonate

Question 25

Types of decomposition reactions?

Answer 25

1. Heating calcium carbonate to produce calcium oxide and carbon dioxide
2. Removal of water from a hydrated material

Question 26

Law of conservation of Mass?

Answer 26

matter cannot be either gained or lost in the process of a chemical reaction

Question 27

What must the total mass of the products equal?

Answer 27

Total mass of the reactants

Question 28

Precipitation Reactions

Answer 28

• Chemical change in a solution that results in one or more insoluble products- To predict if a precipitation reaction can occur it is helpful to know the suitabilities of ionic compounds

Question 29

Theoretical yield

Answer 29

maximum amount of product that can be produced-pencil and paper yield

Question 30

Actual yield

Answer 30

amount produced when the reaction is performed -laboratory yield

Question 31

% yield formula?

Answer 31

%yield = actual yield / theoretical yield x 100%