Compounds (Multivalent, Ionic, molecular, etc.) (Chem GN1)

Question 1

What is an Ionic Compound?

Answer 1

A neutrally charged compound made up of cations and anions.

Question 2

What is an Ionic Bond?

Answer 2

The process of an atom transferring electrons to another atom, forming an ion.

Both atoms must have opposite charges, which then attract each other and form an Ionic compound!

Question 3

Recall!

a) Metals tend to lose electrons to form positive ions called ________

b) Non-metals tend to gain electrons to form negative ions called ________

Answer 3

a) Cations

b) Anions

Question 4

What kind of elements are required to form ionic compounds?

Answer 4

A METAL and NON-METAL

Question 5

Properties of Ionic Compounds

Answer 5

Hard, brittle solids

High melting points

Some are soluble in water

When dissolved in water, the solution can conduct electricity

Question 6

When creating a compound, the ending of an anion’s name must be ___

Answer 6

“ide”

Ex. Oxygen -> Oxide, Phosphorus -> Phosphide

Question 7

Lesson:

Ionic Compounds must establish a NEUTRAL CHARGE by transfering electrons to form OPPOSITELY CHARGED IONS

Answer 7

Example: Sodium (Na) and Oxygen (O)

Sodium has a 1+ charge, whereas Oxygen has a 2-

In order to satisfy each other, their electrons must crisscross!

There must be 1 Oxygen to help sodium, whereas there must be 2 sodiums to help oxygen.

Therefore, our chemical symbol is Na2O (Sodium Oxide)

Question 8

Lesson:

The reason for Sodium Oxide being spelt Na2O and not Na2O1 is because we are trying to simplify the formula as small as possible.

Adding a one would be considered redundant.

Question 9

How can you write formulas for Ionic compounds?

Answer 9

The Zero-sum rule

Crisscross method

(im not explaning. go to ur notes)

Question 10

Practice:

Beryllium Chloride

Answer 10

BeCl2

Question 11

Practice:

Potassium Sulfide

Answer 11

K2S

Question 12

Practice:

Magnesium Oxide

Answer 12

MgO

Remember to simplify :-)

Question 13

What are transition metals?

Answer 13

Transition metals have the ability to form different ions

Ex. Iron may have 2+ or 3+ (depending on what it’s bonding with)

Question 14

What are multivalent Compounds?

Answer 14

Multivalent compounds include atoms that can form multiple different ions.

Question 15

Lesson:

Answer 15

In order to tell what charge is on the ion in a compound, roman numerals are used.

Ex. Iron (II) Chloride - Iron has a Fe 2+ ion.

Question 16

Tip:

Answer 16

If you are trying to figure out the chemical name from a formula, try reverse criss cross.

Ex. Fe2O3 (Iron (III) Oxide)

Question 17

Lesson:

SOMETIMES when you reverse criss-cross, the non-metal may not have the correct charge.

Answer 17

Example: TiO2

When you do the reverse criss cross method, the chemical name turns into Titanium (II) Oxide.

However, that’s not right. Since Oxygen has a charge of 2-, it cannot be 1-

So, if you run into a problem like this, multiply each ion by 2.

Ti - 2 x 2 = 4 O - 1 x 2 = 2

So the name would be: Titanium (IV) Oxide

Question 18

Practice:

Copper (II) Chloride

Answer 18

CuCl2

Question 19

Practice:

PbS

Answer 19

Lead (II) Sulfide

Question 20

What are Polyatomic compounds?

Answer 20

Polyatomic ions are ions made up of more than one atom that acts as a single particle.

The ionic charge of a polyatomic ion is shared over the entire ion rather than being on just one atom.

Question 21

Lesson:

Answer 21

Naming Polyatomic compounds are typically easy. You just include the name of the metal in the beginning and whatever the polyatomic ion is on the next.

Ex. Calcium Hydroxide

Question 22

Lesson:

Answer 22

One thing to note when writing a formula that includes a polyatomic ion:

If you’re required to write a subscript (# of ions) next to a polyatomic ion, make sure to put it in brackets to ensure the subscript applies to every atom in the polyatomic ion.

Ex. Ca(OH)2

The subscript is the 2.

Note: crisscross method still applies to polyatomic ions.

Question 23

Practice:

Calcium Hydroxide

Answer 23

Ca(OH)2

Question 24

Practice:

Na2CO3

Answer 24

Sodium Carbonate

Question 25

What are molecular compounds?

Answer 25

Molecular compounds are pure substances formed when two or more non-metals share electrons to form stable molecules

Question 26

What are Covalent Compounds?

Answer 26

The sharing of electrons form what is called a Covalent bond.

Question 27

What is a diatomic particle?

Answer 27

A molecule consisting of only two atoms of either the same or different elements.

Question 28

What is a combining capacity?

Answer 28

The number of covalent bonds a nonmetal needs to form a stable molecule. Ex. Carbon has a combining capacity of 4

Question 29

Lesson:

Answer 29

Naming Molecular Compounds To name molecular compounds, we add a prefix that indicates the numbers of each atom that is present. The subscript determines the name of the molecular compound. So, if there is a subscript of 2 on nitrogen, then it's Dinitrogen.

Question 30

REMEMBER:

Answer 30

Molecular compounds are two nonmetals.

Question 31

REMEMBER:

Answer 31

The prefix "mono" is excluded from the first element in a compound. Ex. Instead of something being Mononitrogen trichloride, it should be Nitrogen trichloride.

Question 32

Practice: N2O4

Answer 32

Dinitrogen Tetroxide

Question 33

Practice: Nitrogen Trichloride

Answer 33

NCl3

Question 34

A funny word used to remember which elements are diatomic is:

Answer 34

HOFlBrINCl H - Hydrogen O - Oxygen Fl - Fluorine Br - Bromine I - Iodine N - Nitrogen Cl - Chlorine

Question 35

Remember:

Answer 35

Covalent bonds and Molecular compounds are formed by two non-metals Ionic compounds are formed by a metal and non-metal

Question 36

Something to keep in mind:

Answer 36

Remember to simplify compounds if you are able to :-).