Chapter 1: 1.1 Atoms, Molecules, and Moles

Question 1

Atoms consist of:

Answer 1

Protons
Neutrons
Electrons

Question 2

Charge of proton

Answer 2

Positive

Question 3

Charge of neutron

Answer 3

Electrically neutral

Question 4

Charge of electron

Answer 4

Negative

Question 5

Do protons and neutrons have the same mass?

Answer 5

Almost the same mass

Question 6

The mass of an electron is only ______th of the mass of a proton or a neutron

Answer 6

1/1836

Question 7

Atomic number

Answer 7

The number of protons in an atomic nucleus

Question 8

Where are protons and neutrons found?

Answer 8

In the atom’s nucleus

Question 9

Mass number

Answer 9

The total number of protons and neutrons in an atom

Question 10

Atomic mass unit

Answer 10

The chemical unit of atomic mass, also known as Dalton

Question 11

Define 1 u (atomic mass unit)

Answer 11

Exactly 1/12 of the mass of a C-12 atom

Question 12

What is Dalton denoted by?

Answer 12

“Da”

Question 13

Isotopes

Answer 13

Atoms with the same number of protons but different numbers of neutrons

Question 14

Isotopes have the same ____ number but a different ____ number

Answer 14

Same atomic number
Different mass number

Question 15

Isotopic abundance

Answer 15

The percent by number of each of the isotopes of an element

Question 16

Average atomic mass

Answer 16

The average of the masses of all of the isotopes of that element

Question 17

Why is it that the atomic mass an element less than the atomic mass of the nucleus?

Answer 17

When protons and neutrons combine to form a nucleus, some of their total mass is converted into energy

Question 18

What is the difference between the atomic mass of an element and the atomic mass of the nucleus known as?

Answer 18

Mass Defect

Question 19

Neutral atom

Answer 19

Atoms that have an equal number of protons and electrons

Question 20

Cation

Answer 20

Atom with a positive charge

Question 21

Anion

Answer 21

Atom with a negative charge

Question 22

What are ions of molecules called?

Answer 22

Molecular (or complex) ions

Question 23

Compound

Answer 23

A molecule containing atoms of more than one element

Question 24

Is O2 a compound?

Answer 24

No

Question 25

Diatomic molecule

Answer 25

A molecule with only two atoms (such as O2)

Question 26

Polyatomic molecule

Answer 26

A molecule with more than two atoms (such as H2O)

Question 27

Empirical formula

Answer 27

Represents the simplest ratio of the numbers of atoms in a molecule

Question 28

What is the empirical formula of glucose (C6H12O6)?

Answer 28

CH2O

Question 29

Define a mole

Answer 29

The number of atoms contained in exactly 12 grams of pure carbon-12

Question 30

What is the symbol for number of moles

Answer 30

n

Question 31

Determine the number of individual atoms, molecules, or ions in a sample

Answer 31

Moles * Avogadro's number

Question 32

What is the number of atoms contained in exactly 12 grams of pure carbon-12 known as?

Answer 32

Avogadro's number (6.02 * 10^23)

Question 33

1 mole of carbon-12 = __ grams

Answer 33

12 grams of carbon-12

Question 34

If one mole of carbon-12 atoms has a mass of exactly 12 g, what is the mass in grams per mole for carbon-12?

Answer 34

12 grams per mole

Question 35

Unit used for the mass of one atom

Answer 35

u

Question 36

Unit used for the mass of a mole of atoms

Answer 36

g

Question 37

Molecular mass

Answer 37

The mass of one molecule computed as the sum of atomic masses of all the atoms in the molecule

Question 38

What is molecular mass usually expressed in?

Answer 38

Atomic mass units

Question 39

Molar mass (MM)

Answer 39

The mass of one mole of molecules

Question 40

What is the unit for molar mass?

Answer 40

Grams per mole

Question 41

Formula of mass percent

Answer 41

(Mass of one species / Total mass of sample) * 100%

Question 42

Mass percent of a species cannot exceed ____

Answer 42

Cannot exceed 100%

Question 43

Sum of mass percents must add up to:

Answer 43

100%

Question 43

Formula of mole fraction

Answer 43

(Number of moles of one species / Total number of moles)

Question 44

Formula of Mole percent

Answer 44

Mole fraction * 100%

Question 45

What is used to represent to mole fraction of an element or compound?

Answer 45

The symbol X with a subscript of the element or compound

Question 46

Solution

Answer 46

A homogeneous mixture of two or more substances

Question 47

Solute

Answer 47

Substance Dissolved

Question 48

Solvent

Answer 48

Dissolving substance

Question 49

Molarity

Answer 49

The number of moles of solute in one litre of the solution

Question 50

Symbol for molarity

Answer 50

M

Question 51

Formula for molarity

Answer 51

Amount of solute / Volume of solution or M = n/V

Question 52

True or False: When calculating molarity, volume can be calculated using millilitres or litres

Answer 52

False, when calculating molarity, volume can only be calculated using liters

Question 53

Dilution

Answer 53

The process of reducing the concentration of a solution, either by adding the solvent or buy adding another solution

Question 54

Provided no chemical reaction takes place, when a solution is diluted with the solvent, or mixed with a solution of another substance, does the number of moles of solute change?

Answer 54

No

Question 55

Define a chemical reaction

Answer 55

A process in which one set of substances, called reactants, is converted to a new set of substances, called products

Question 56

What is the literal meaning of stoichiometry?

Answer 56

"The measurement of elements"

Question 57

Theoretical yield

Answer 57

The expected amounts of products (can be calculated)

Question 58

Actual yield

Answer 58

The amount of product collected

Question 59

Percent yield

Answer 59

The ratio of the actual yield to the theoretical yield

Question 60

True or False: Actual and theoretical yields can be expressed in different units when calculating percent yield

Answer 60

False, they must both be expressed in the same units (moles or masses)

Question 61

Limiting reagant

Answer 61

The reagent whose amount (number of moles) is insufficient to react completely with all the other reagents, as determined by the stoichiometry of the reaction