Chemical bonding

Hydroxide ion

OH-

Nitrate ion

NO3-

Hydrogencarbonate ion

HCO3-

Permanganate ion

MnO4-

Carbonate ion

CO3 2-

Chromate ion

CrO4 2-

Dichromate ion

Cr2O7 2-

Sulfate ion

SO4 2-

Sulfite ion

SO3 2-

Thiosulfate ion

S2O3 2-

Phosphate ion

PO4 3-

Ammonium ion

NH4+

-ide

A compound that contains only 2 elements

-ate

A compound that contains oxygen and 2 other elements

Electronegativity for ionic bonding

Greater than 1.7

Polar covalent bonding

Between 0.4 and 1.7. Unequal sharing of electrons.

Non polar covalent bond

Equal sharing of electrons. Difference is less than or equal to 0.4. If the molecule is symmetrical it becomes non polar.

Linear shape

2 bonds, 0 lone pairs, 180 degrees

Trigonal planar

3 bonds, 0 lone pairs, 120 degrees

Tetrahedral

4 bonds, 0 lone pairs, 109.5 degrees

Pyramidal

3 bonds, 1 lone pair, 107 degrees

V-shaped

2 bond pairs, 2 lone pairs, 104.5 degrees

Anions

Negatively charged ions

Cations

Positively charged ions

Chloride ion (Cl-

Chloride salt (NaCl) is added to a test tube of water. Add silver nitrate (AgNO3) and a white precipitate is formed (silver chloride). When ammonia is added the precipitate should dissolve.

Nitrate ion (NO3-)

Add a few drops of Iron(II) sulfate and no observation will be made. Add sulfuric acid a brown ring is formed.

Phosphate ion (PO4 3-)

Add ammonium molybdate and there will be no visible changes. Add nitric acid and a yellow precipitate will form.

Sulfate (SO4 2-)

Add barium chloride (BaCl2) and a white precipitate is formed. When HCl is added the precipitate remains.

Sulfite (SO3 2-)

Add barium chloride (BaCl2) and a white precipitate is formed. When HCl is added the white ppt dissolves.

Carbonate (CO3 2-)

Add hydrochloric acid and fizzing will take place as CO2 gas is produced. The limewater turns milky. To distinguish add magnesium sulfate (MgSO4) and a white ppt is formed.

Hydrogencarbonate (HC03 -)

Add hydrochloric acid and fizzing will take place as CO2 gas is produced. The limewater turns milky. To distinguish add magnesium sulfate (MgSO4) and a no precipitate is formed.