Chapter 3 - Molecules, Compounds, And Chemical Equations

Question 1

The properties of a compound are ____ from the constituent elements.

Answer 1

Totally different (think H20 vs 0)

Question 2

____ ____ are forces of attraction between atoms.

Answer 2

Chemical bonds

Question 3

The bonding attraction comes from attraction between ____ and ____.

Answer 3

Protons and Electrons

Question 4

___ bonds result when electrons have been transferred between atoms.

Answer 4

Ionic

Question 5

When do Ionic bonds generally occur?

Answer 5

When metal atoms bond to nonmetal atoms.

Question 6

____ bonds result when two atoms share some of their electrons.

Answer 6

Covalent

Question 7

When do covalent bonds generally occur?

Answer 7

When nonmetal atoms bond together.

Question 8

The number of ____ is written to the right of the element as a subscript.

Answer 8

Atoms

Question 9

• Gives the relative number of atoms of each element in a compound.
• Does not describe how many atoms, the order of attachment, or shape.
• Used for ionic compounds

Answer 9

Empirical Formula

Question 10

• Gives the actual number of atoms of each element in a molecule of a compound.
• Does not describe the order of attachment, or the shape.

Answer 10

Molecular Formula

Question 11

• Uses lines to represent covalent bonds and shows how atoms in a molecule are connected or bonded to each other.
• does not directly describe the 3D shape.

Answer 11

Structural Formula

Question 12

Uses balls to represent the atoms and sticks to represent the attachments between them.

Answer 12

Ball-and-stick Models

Question 13

Uses interconnected spheres to show the electron clouds of atoms connecting together.

Answer 13

Space-filling Models

Question 14

Elements whose particles are single atoms

Answer 14

Atomic Elements

Question 15

Elements whose particles are multi-atom molecules

Answer 15

Molecular Elements

Question 16

Compounds whose particles are molecules made of only nonmetals

Answer 16

Molecular Compounds

Question 17

Compounds whose particles are cations and anions

Answer 17

Ionic Compounds

Question 18

____ elements occur as 2 atom molecules.

Answer 18

Diatomic

Question 19

What is the rule of 7?

Answer 19

• Remember Hydrogen
• Go to Nitrogen (7)
• Move 2 to the side and then 3 down
• this creates a 7

Question 20

Classify each of the following as either an atomic element, molecular element, molecular compound, or ionic compound

1) Aluminum, Al
2) Aluminium Chloride, AlCl3
3) Chlorine, Cl2
4) Acetone, C3H6O
5) Carbon Monoxide, CO
6) Cobalt, Co

Answer 20

1) Atomic Element
2) Ionic compound
3) Molecular Element
4) Molecular Compound
5) Molecular Compound
6) Atomic Element

Question 21

Because we must balance the charge, if Na+ is combined with S2-, you will need ____ Na+ ions for every ____ S2-, therefore the formula must be ___

Answer 21

2 Na+ for every 1 S2-, resulting in Na2S

Question 22

What is the Formula steps for Ionic Compounds?

Answer 22

1) Write the Symbol for the Metal cation and it’s charge
2) Write the Symbol for the nonmetal anion and it’s charge
3) Charge (without sign) becomes subscript for the other ion
4) Reduce subscripts to smallest whole number ratio
5) Check that the sum of the charges of the cations cancels the sum of the anions

Question 23

What are the formulas for compounds made of the following ions?

1) Potassium ion with a nitride ion
2) Calcium ion with a bromide ion
3) Aluminum ion with a sulfide ion

Answer 23

1) K3N
2) CaBr2
3) Al2S3

Question 24

To name a cation:

1) Metal with invariant charge =
2) Metal with variable charge=
3) Polyatomic ion =

Answer 24

1) Metal name
2) Metal name (charge)
3) Memorize

Question 25

To name an anion: 1) Nonmetal = 2) Polyatomic ion =

Answer 25

1) Stem of nonmetal name + ide | 2) Memorize

Question 26

Naming Binary Ionic Compounds for Metals with Invariant Charge

Answer 26

1) Name Metal cation first, Name nonmetal anion 2) cation name is the metal name 3) nonmetal name is changed by adding -ide Ex: CsF = Cesium Fluoride

Question 27

Name the following compounds: 1) KCl 2) MgBr2 3) Al2S3

Answer 27

1) Potassium Chloride 2) Magnesium Bromide 3) Aluminum Sulfide

Question 28

Naming Binary Ionic Compounds for Metals with variable charge

Answer 28

1) Name Metal cation first, Name nonmetal anion second 2) Metal cation name is the metal name followed by a Roman number in parentheses to indicate the charge 3) Nonmetal anion named by changing the ending on the nonmetal name to -ide

Question 29

Name the following compounds: 1) TiCL4 2) PbBr2 3) Fe2S3

Answer 29

1) Titanium(IV) Chloride 2) Lead(II) Bromide 3) Iron(III) Sulfide

Question 30

What are the formulas for compounds made from the following ions? 1) Copper(II) Ion with a Nitride Ion 2) Iron(II) Ion with a Bromide Ion

Answer 30

1) Cu3N2 | 2) FeBr2

Question 31

____ are ionic compounds containing a specific number of waters for each formula unit.

Answer 31

Hydrates

Question 32

In a formula, attached waters follow ___.

Answer 32

•, Ex: CoCl2•6H20

Question 33

In name attached waters indicated by ____ + hydrate after name of ionic compound.

Answer 33

Prefix, Ex: Cobalt(II) Chloride Hexahydrate

Question 34

Hydrate Prefixes 1) hemi 2) mono 3) di 4) tri 5) tetra 6) penta 7) hexa 8) hepta 9) octa

Answer 34

1) 1/2 2) 1 3) 2 4) 3 5) 4 6) 5 7) 6 8) 7 9) 8

Question 35

Writing Names of Binary Molecules Compounds of Two Nonmetals

Answer 35

1) Write Name of first element in formula a) element furthest left and down b) use the full name of the element 2) Writes Name the second element in the formula with an -ide suffix 3) Use prefix in front of each name to indicate the number of atoms a) Never use the prefix mono- on the first element

Question 36

Name the following binary molecules: 1) BF3 2) NO2 3) PCl5 4) I2F7

Answer 36

1) Boron Trifluoride 2) Nitrogen Dioxide 3) Phosphorus Pentachloride 4) Diiodine Heptafluoride

Question 37

Write Formulas for the Following: 1) Dinitrogen Tetroxide 2) Sulfur Hexafluoride 3) Diarsenic Trisulfide

Answer 37

1) N204 2) SF6 3) As2S3

Question 38

What are some qualities of Acids?

Answer 38

* Molecular compounds that form H+ when dissolved in water * Sour taste * Dissolve many metals (not noble metals) * Formula generally starts with H, Ex: HCl

Question 39

____ Acids habe H+1 cation and nonmetal anion (only two elements).

Answer 39

Binary

Question 40

____ have H+ cation and polyatomic anion.

Answer 40

Oxyacids

Question 41

Naming Binary Acids

Answer 41

* Write a hydro prefix * Follow with the nonmetal name * Change ending on nonmetal name to -ic * Write the wird acid at the end of the name

Question 42

Name the binary acid HCl(aq)

Answer 42

Hydrochloric Acid

Question 43

Naming Oxyacids

Answer 43

* If polyatomic ion Name ends in -ate, then change ending to -ic suffix * If polyatomic ion Name ends in -ite, then change ending to -ous suffix * Write wird acid at the end of all names

Question 44

Name the oxyacid H2SO4(aq)

Answer 44

Sulfuric Acid

Question 45

What are the formulas for the following acids? 1) Chlorous acid 2) Phosphoric Acid 3) Hydrobromic Acid

Answer 45

1) HClO2 2) H3PO4 3) HBr

Question 46

How many moles are in 50.0g of PbO2? (Pb = 207.2, O = 16.00)

Answer 46

0.209molPbO2

Question 47

What is the Mass of 4.78x1024 NO2 molecules?

Answer 47

365gNO2

Question 48

What can the percentage composition be determined by?

Answer 48

* The formula of the compound | * The experimental mass analysis of the compound

Question 49

Formula for Percent Composition

Answer 49

Percentage = (part/whole) x 100%

Question 50

Find the mass percent of Cl in C2Cl4F2

Answer 50

69.58%

Question 51

The ____ ____ tells you the mass of a constituent element in 100g of compound.

Answer 51

Mass percent

Question 52

Benzaldehyde is 79.2% carbon. What mass of benzaldehyde contains 19.8g of C?

Answer 52

25.0g benzaldehyde

Question 53

Which formula is the simplest, whole-number ratio of the atoms of elements in a compound?

Answer 53

Empirical Formula

Question 54

Finding an Empirical Formula

Answer 54

* Convert the percentages to grams (100g) * Convert grams to moles * Write a pseudo formula using moles as subscripts * Divide all by smallest number of moles * Multiply all mole ratios by number to make all whole numbers

Question 55

Determine the Empirical Formula of Stannous fluoride,which contains 75.7% Sn (118.70) and the rest fluorine (19.00)

Answer 55

Sn1F2

Question 56

Determine the Empirical Formula of magnetite, which contains 72.4% Fe (55.85) and the rest oxygen (16.00)

Answer 56

Fe3O4

Question 57

What do you need to determine the molecular formula?

Answer 57

You need to know the Empirical also formula and the molar mass of the compound.

Question 58

Benzopyrene has a molar mass of 252 g/mol and an empirical formula of C5H3. What is its molecular formula? (C =12.01, H= 1.01)

Answer 58

(252 g/mol/63.08 g/mol) = 4

Question 59

* A common technique for analyzing compounds is to burn a known mass of compound and weight the amounts of product made. * Generally used for organic compounds containing C, H, O.

Answer 59

Combustion Analysis

Question 60

* Involve chemical changes in matter resulting in new substances * Involve rearrangement and exchange of atoms to produce new molecules

Answer 60

Chemical Reactions

Question 61

• Shorthand way of describing a reaction • Provides information about - Formulas of reactants and products - States of reactants and products - Relative numbers of reactants and product molecules that are required - Can be used to determine weights of reactants used and products that can be made

Answer 61

Chemical Equations

Question 62

Methane gas burns to produce ___ ___ gas and ____ ____.

Answer 62

Dioxide gas and gaseous water

Question 63

Whenever something burns it combines with

Answer 63

O2(g)

Question 64

To show the reaction obeys the Law of Conservation of Mass the equation must be

Answer 64

Balanced

Question 65

The (g) after the Formulas tells us the ____ of the chemical

Answer 65

State

Question 66

The number in front of each substance tells us the numbers of those molecules in a reaction

Answer 66

Coefficients

Question 67

An equation is balanced if

Answer 67

There are equal numbers of atoms of each element on the reactant and product sides

Question 68

Symbols indicating the state after chemicals 1) (g) 2) (l) 3) (s) 4) (aq)

Answer 68

1) gas 2) liquid 3) solid 4) aqueous = dissolved in water

Question 69

Energy symbols used above the arrow for decomposition reactions 1) D 2) hn 3) shock 4) elec

Answer 69

1) heat 2) light 3) mechanical 4) elec

Question 70

Write a balanced equation for Al(s) + O2(g) = Al2O3(s)

Answer 70

4Al(s)+3O2(g)= 2Al2O3(s)

Question 71

Write a balanced equation for | Al(s) + 6HC2H3O2(aq) = Al(C2H3O2)3(aq) + 3H2(g)

Answer 71

2Al(s) + 6HC2H302(aq) = 2Al(C2H302)3(aq) + 3H2(g)

Question 72

In the 18th Century, compounds from living things were called

Answer 72

Organic

Question 73

In the 18th Century, compounds from the nonliving environment were called

Answer 73

Inorganic

Question 74

____ compounds easily decomposed and could not be made in the 18th Century lab

Answer 74

Organic

Question 75

____ compounds were very difficult to decompose, but were able to be synthesized

Answer 75

Inorganic

Question 76

Today we commonly make ___ compounds in the lab and find them all around us.

Answer 76

Organic

Question 77

Organic compounds are mainly made out of

Answer 77

Carbon and Hydrogen, sometimes with O, N, S, P

Question 78

Carbon atoms bond almost exclusively

Answer 78

Covalently

Question 79

When Carbons bonds, it forms ____ covalent bonds

Answer 79

4

Question 80

Carbon is unique in that it can form ___ chains of C atoms, both straight and branched, and rings of C atoms.

Answer 80

Limitless

Question 81

What are the 2 main categories of organic compounds?

Answer 81

Hydrocarbons and functionalities hydrocarbons

Question 82

___ contain only C and H

Answer 82

Hydrocarbons

Question 83

Most files are mixtures of

Answer 83

Hydrocarbons

Question 84

What are some common hydrocarbons?

Answer 84

Methane, Propane, n-Butane, n-Pentane, Ethene, and Ethyne