1.3 Chemical Compounds

Name some of the similarities and differences between Potassium Chloride and Potassium Chlorate

• KCl is used to treat medication conditions like heart attacks

• KClO₃ is toxic; key ingredient in explosives

• Both sound similar

• KCl ends in ide; KClO₃ ends in ate

• Both compounds have Potassium and Chlorine

• KClO₃ has oxygen

“A pure sample of an element would contain all the same types of _____ and all of them would have the same number of _____”

• “atoms”

• “protons”

“The vast array of material on earth cannot be made without doing what?

• Combining the 118 elements found on the periodic table

“Most matter on earth is actually found as-”

• “-compounds”

Define compound

• Combinations of two or more elements

Describe Hydrogen and Oxygen in terms of atoms and molecules

• Hydrogen atoms

• O₂ molecules

• H₂O molecules (compound)

Atoms contain what 3 things?

• Protons

• Electrons

• Neutrons

Bohr theorized that an atom is most stable when?

• When it contains 8 electrons in its outermost shell

What is the outermost shell called?

• Valence shell

When the valence shell is full and the atom is stable, what is that called?

• The Octet Rule

Neon has 10 electrons. What does this mean in terms of stability?

• Neon is very stable

• First shell is full with 2 electrons, second shell is full with 8 electrons

• Does not want to combine or react with itself or any other element

When an element doesn’t have a full valence shell, what does it have a tendency to do?

• Tendency to gain or lose electrons to satisfy the Octet Rule and become stable

When an atom gains/loses electron(s) causing it to have +/- than protons, it is now called what?

An ion

Sodium has 11 electrons- how could it become stable?

• Has only 1 electron in its valence shell

• Much easier to get rid of 1 electron than to gain 7

Why is it easier for Sodium to lose 1 electron than gain 7?

• Requires less energy to just lose 1

When sodium loses its 1 valence electron what does it become?

• A sodium ion

What would be sodium’s charge now what it lost an electron? How would you write it?

• Charge of +1

• Na¹⁺ or Na⁺

Why do sodium and chloride love each other?

• Because Sodium has 1 valence electron and Chloride has 7

• If Sodium gives it’s 1 electron to Chloride they because stable together as NaCl

What is interesting about all the Alkali Metals in the first column of the periodic table?

• They all have 1 valence electron

• Usually lose them

• Charge is ⁺¹ because they’ve lost an electron (-)

A positively (+) charged ion is called what?

• Cation

A negatively (-) charged ion is called what?

• Anion

Alkali Earth Metals have how many valence electrons? What is their charge?

• 2 valence electrons

• ⁺²

Do Transition Metals follow a similar pattern to Alkali Metals and Alkaline Earth Metals?

• No

Does family 13 on the periodic table follow a pattern?

• Yes

• ⁺³

Chlorine’s anion is called what?

• Chloride

Chloride ion has a net charge of what?

• ^-1

Lewis Structures are also called what?

• Electron Dot Diagrams

What is only shown on Lewis Diagrams?

• Valence electrons

What must you remember to draw when doing a Lewis Structure for an ion?

• Brackets

What would the Lewis Structure look like for both Na (loses an electron) and Cl (gains an electron)?

“Atoms become ____ when they combine to form _____ _____”

• “ions”

• “ionic compounds”

Compounds made of a combinations of what 2 things are called ionic compounds?

• Cations (+ ions) and Anions (- ions)

If a Chlorine atom and a Sodium atom collide, what happens?

• The Chlorine attracts the Sodium’s electron

• Now they both become stable

The bond that arrises when oppositely charged ions attract one another is called what?

• An ionic bond

Describe the attraction between + and - ions. What’s a real world example that’s simliar?

• They are electrostatically attracted to one another

• Magnets

What does IUPAC stand for and what do they do?

• International Union of Pure and Applied Chemistry

• Develop worldwide rules to name and write formulas for compounds

Define metals in relation to the periodic table

• Left of the table

• Does not include Hydrogen

• Shiny, malleable elements that conduct heat and electricity well

• Most are solid at room temp

• Tend to form positive (+) ions

Define non-metals in relation to the periodic table

• Right side of the table

• Includes Hydrogen

• Have more varied properties than metals

• Poor conductors of heat and electricity

• Commonly form negative (-) ions

Define metalloids in relation to the periodic table

• Zig-zag on the right side

• Border between metals and non-metals

• Properties of both metals and non-metals

What is the name for the simplest type of ionic compound?

• Binary ionic compounds

Binary ionic compounds consist of what 2 things?

• 1 metal and 1 non-metal

When naming a binary ionic compound, what comes first- the metal or the non-metal?

• The metal

For binary ionic compounds, the non-metal goes second and what happens to the suffix?

• It becomes -ide

What is strange about FeO?

• Is Iron Oxide

• BUT there is more than one type of iron oxide because there is more than one common oxidation state of iron

What do the 2 and 3 in the top right corner mean?

• Called “oxidation states”

• Represent the 2 most stable ions iron can form

What is special about transition metals and ions?

• Most transition metals can form two types of ions

If Iron ions can be +2 or +3, how would you write them?

• Iron (II) Oxide

• Iron (III) Oxide

• *Roman numerals

When looking at a compound, how do you determine which Roman numeral to use?

• Once you find the oxidative states of both elements, they must have an equal charge but with the opposite sign

How would you name FeCl₂?

• Cl₂ means there’s 2 of them. Chlorine has 7 valence electrons so each Cl wants 1 electron to be complete. So each has a charge of -1

• Because there’s two of them, (-1) + (-1) = -2

• The sides have to be equal

• So, this is Iron(II) Chloride

For what 4 elements would you never use Roman numerals with?

1. Silver (Ag)

2. Zinc (Zn)

3. Cadmiun (Cd)

4. Scandium (Sd)

Define polyatomic ionic compounds

• Compounds that contain 3 or more elements

What are polyatomic ionic compounds composed of?

• A metal that always comes first

• And a cluster of non-metals

What are a cluster of non-metals called?

• A polyatomic ion

What is the KEY to writing formulas for ionic compounds?

• Overall net charge must be 0

What do we call oxygen when it has a charge?

• Oxide

How would you go about writing the formula for Aluminum Oxide?

• Aluminum has a charge of +3; Oxygen has a charge of -2

• They MUST balanced

• The easiest way it to get them both to 6 meaning two Aluminums and three Oxygens

• We end up with Al₂O₃

Describe the criss-cross method for Magnesium Bromide

• Begin with Mg Br

• Mg has a charge of 2; Br has a charge of (-) 1

• Cross them meaning Mg gets the 1 and Br gets the 2

• Final is MgBr₂

Using the criss-cross method, what is special about Calcium Oxide?

• Both have a charge of 2 so it becomes Ca₂O₂

• Because they’re the same number they can be removed

• Final is CaO

Describe the cross-cross method with Copper Nitrate

• Cu has a charge of 2; NO₃ has a charge of 1

• Cu₁ just becomes Cu

• NO₃ becomes (NO₃)₂

• Final is Cu(NO₃)₂

How would you write the formula for Iron(II) Nitride?

• Fe has 2; N has 3

• Becomes Fe₃N₂

“A covalent bond forms when two _____ react with one another”

• “non-metals”

“Compounds that contain covalent bonds are classified as _____”

• “covalent compounds”

What is another name for covalent compounds?

• Molecular compounds

In naming covalent compounds, what pattern do we go by?

• Greek prefixes

Name the greek prefixes from 1 to 10

1. Mono

2. Di

3. Tri

4. Tetra

5. Penta

6. Hexa

7. Hepta

8. Octa

9. Nona

10. Deca

Using Greek prefixes, how would you name N₂O?

• Dinitrogen Monoxide

In naming covalent compounds, what happens to the end of the second element?

• End changes to -ide

What is different about naming PCl₃?

• It would not be Monophosphorous

• If the first non-metal is only 1, we don’t add a Greek prefix

• Would be Phosphorous Trichloride

Naming compounds with transition metals: how would you name CuS?

• Copper(II) sulphide

• Sulfur has a charge of -2 which means Copper needs to have a charge of +2 to balance

• Copper’s oxidative states are 2 or 1 so it would be 2 to balance

Naming compounds with transition metals: how would you name PbI₄?

• Lead(IV) Iodide

• There are 4 Iodine atoms. Iodine has a charge of -1 so 4 X -1 = -4

• This must balance. Lead has oxidative states of 2 or 4 so it must be 4

Naming compounds with transition metals: how would you name ZnO?

• Zinc Oxide

• Oxygen has a charge of -2. Zinc only has one oxidative state of 2

• This means they cancel each other out

• Don’t add any Roman Numerals

Naming compounds with transition metals: how would you name Au₃N?

• Gold(I) Nitride

• Nitrogen has a charge of -3

• Gold has oxidative states of 3 and 1. Because there’s _{3 atoms of Gold,} 3 X 1 = 3 to balance

Naming polyatomic ionic compounds: Li₃PO₄

• Lithium Phosphate

• Phosphate has a charge of -3

• Lithium has one oxidative state of 1. There’s _{3 atoms} so 1 X 3

• No roman numerals

Naming polyatomic ionic compounds: NaHSO₄

• Sodium Hydrogen Sulphate

• HSO₄ has a charge of -1

• Na only has one oxidative state of 1. Balances

• No Roman Numerals

Naming polyatomic ionic compounds: Fe₂(CO₃)₃

• Fe has oxidative states of 2 and 3

• Carbonate has a charge of -2. -2 X 3 = -6

• Fe 3 X 2 = 6

Naming polyatomic ionic compounds: NH₄NO₃

• Ammonium Nitrate

• NO₃ has a charge of -1

• Ammonium (NH₄) is not an element and is not on the periodic table. It has a charge of 1. Balance, cancel out

• No Roman Numerals

Naming polyatomic ionic compounds: K₂Cr₂O₇

• Potassium Dichromate

• Dichromate has a charge of -2

• Potassium has only one oxidative state of 1. 1 X 2 = 2. Balanced

• No Roman Numerals

Naming polyatomic ionic compounds: AgClO₃

• Silver Chlorate

• Chlorate has a charge of -1

• Silver only has one oxidative state of 1. Balanced

• No Roman Numerals

Naming polyatomic ionic compounds: Pb(OH)₂

• Lead(II) Hydroxide

• OH has a charge of -1. -1 X 2 = -2

• Pb has oxidative states of 2 and 4. Must be 2 to balance

Writing formulas for Ionic Compounds: Magnesium Bromide

• MgBr₂

• Cross-Cross Method

• Magnesium has a charge of 2; Bromide has a charge of -1

• Cross them, eliminate the 1

Writing formulas for Ionic Compounds: Calcium Oxide

• CaO

• Criss-cross

• Calcium has a charge of 2; Oxide has a charge of -2

• Cancel each other out

Writing formulas for Ionic Compounds: Copper(II) Nitrate

• Cu(NO₃)₂

• Copper is 2

• Nitrate (NO₃) has a charge of -1

Writing formulas for Ionic Compounds: Potassium Oxide

• K₂O

• Potassium has a charge of 1

• Oxide has a charge of -2

Writing formulas for Ionic Compounds: Zinc Bromide

• ZnBr₂

• Zinc has a charge of 2

• Bromide has a charge of -1

Writing formulas for Ionic Compounds: Iron(III) Nitride

• FeN

• Iron has a charge of 3

• Nitride has a charge of -3

Writing formulas for Ionic Compounds: Iron(II) Nitride

• Fe₃N₂

• Fe has a charge of 2

• Nitride has a charge of -3

Writing formulas for Ionic Compounds: Magnesium Phosphate

• Mg₃(PO₄)₂

• Magnesium has a charge of 2

• Phosphate has a charge of -3

Writing formulas for Ionic Compounds: Cobalt(II) Oxalate

• CoC₂O₄

• Cobalt has a charge of 2

• Oxalate (C₂O₄) has a charge of -2

Naming Covalent Compounds: N₂O

• Dinitrogen Monoxide

• ₂ is di so Nitrogen becomes Dinitrogen

• ₁ is mono so Oxygen becomes Monoxide

Naming Covalent Compounds: PCl₃

• Phosphorous Trichloride

• ₁ in the first non-metal means mono is dropped

• ₃ is tri so Chlorine becomes Trichloride

Naming Covalent Compounds: C₃S₂

• Tricarbon Disulphide

• ₃ is tri so it become Tricarbon

• ₂ is di so it becomes Disulphide

Naming Covalent Compounds: P₂O₃

• Diphosphorous Trioxide

• ₂ is di so it becomes Diphosphorous

• ₃ is tri so it becomes Trioxide

Naming Covalent Compounds: Cl₂O

• Dichlorine Monoxide

• ₂ is di so it becomes Dichlorine

• ₁ is mono so it becomes Monoxide

Naming Covalent Compounds: SF₆

• Sulfur Hexafluoride

• ₁ is mono but it’s first so it’s dropped becoming Sulfur

• ₆ is Hexa so it becomes Hexafluoride

Formula for Covalent Compounds: Nitrogen Monoxide

• NO

• If the first is just the element there will be no subscript/prefix

• Mono means 1 but we don’t write a subscript for 1

Formula for Covalent Compounds: Iodine Pentafluoride

• IF₅

• If the first is unchanged from the element there will be no subscript

• Penta is 5

Formula for Covalent Compounds: Carbon Tetrachloride

• CCl₄

• Carbon is unchanged so no subscript

• Tetra is 4