Review – CHEMISTRY Unit
Answer Key
Periodic Table, Ionic & Molecular Compound
1. Draw a Bohr-Rutherford diagram for sodium: Show nucleus with 11 protons, 1st orbit with 2 electrons,
2nd orbit with 8 electrons and 3rd orbit with 1 electrons.
2. For the following elements, once they gain/lose electrons, identify the ionic charge, whether it’s cation or anion
and the ion’s name:
Ca: Ca2+ , cation, calcium ion
S: S2- , anion, sulfide ion
Li: Li1+, cation, lithium ion
K: K1+ , cation, potassium ion
Cl: Cl1- , anion, chloride ion
3. Identify the product when the following elements combined:
Ions formed
Formula
Name
Calcium & oxygen
Ca2+ and O2-
CaO
calcium oxide
Potassium & oxygen
K1+ and O2-
K2O
potassium oxide
Sodium & fluorine
Na1+ and F1-
NaF
sodium fluoride
Aluminum & nitrogen
Al3+ and N3-
AlN
aluminum nitride
4. Complete the missing formula or compound name:
Also identify as ionic or molecular compound
Formula:
PbCl2
Compound name:
Lead (II) chloride
Compound:
Ionic
Formula:
Fe(NO3)3
Compound name:
Iron (III) nitrate
Compound:
Ionic
PCl3
Phosphorus trichloride
Molecular
P2O5
Molecular
FeBr3
Iron (III) bromide
Ionic
NH4OH
Diphosphorus
pentaoxide
Ammonium hydroxide
MnO2
Manganese (IV) oxide
Ionic
PbO2
Lead (IV) oxide
Ionic
CuCl2
Copper (II) chloride
Ionic
PCl5
Molecular
NaOH
Sodium hydroxide
Ionic
CuSO4
Phosphorus
pentachloride
Copper (II) sulfate
FeO
Iron (II) oxide
Ionic
SO2
Sulfur dioxide
Molecular
Fe2(SO4)3
Iron (III) sulfate
Ionic
H2SO4
Sulfuric acid
Molecular
SF4
Sulfur tetrafluoride
Molecular
CuBr
Copper (I) bromide
Ionic
Na2S
Sodium sulfide
Ionic
AgNO2
Silver nitrite
Ionic
Ionic
Ionic
Na2SO4
Sodium sulfate
Ionic
Al(HCO3)3
Aluminum bicarbonate
Ionic
SnS
Tin (II) sulfide
Ionic
NI3
Nitrogen triiodide
Molecular
MnO2
Manganese (IV) oxide
Ionic
Al2S3
Aluminum sulfide
Ionic
(NH4)2SO4
Ammonium sulfate
Ionic
N2O4
Dinitrogen tetroxide
Molecular
Acids Formula:
H2S
Compound name:
Hydrosulfuric acid
Base Formula:
Ca(OH)2
Compound name:
Calcium hydroxide
HBr
Hydrobromic acid
NaHCO3
Sodium bicarbonate
H2SO4
Sulfuric acid
NH4OH
Ammonium hydroxide
H2CO3
Carbonic acid
Al(OH)3
Aluminum hydroxide
HNO3
Nitric acid
Mg(OH)3
Magnesium hydroxide
5. State characteristics of acids vs. base
(See p. 271 of textbook)
Acids are molecular compounds that react with metals. In solutions, acids react with metals, conduct electricity
and change blue litmus paper to red colour.
Bases are ionic compounds, many are hydroxides. In aqueous solutions they conduct electricity and change red
litmus paper to blue colour.
Types of reactions & Balancing
1. Identify these types of reaction:
AB + C  A + CB
Single displacement
A + B  AB
Synthesis
AB  A + B
Decomposition
AB + CD  AD + CB
Double displacement
2. For each identify the name of the reactants, the type of reactions, formula and name of products formed and
balance the equation:
Fe + CuSO4
iron + copper (II) sulfate
(Single displacement)
 FeSO4 + Cu
 iron (II) sulfate + copper
2 KI + Pb(NO3)2
potassium iodide + lead (II) nitrate
(Double displacement)
 2 KNO3 + PbI2
 potassium nitrate + lead (II) iodide
C4H10 + O2
 CO2 + H2O
(Note: No need to name C4H10 – it’s butane for those that are curious)
Butane + oxygen
 Carbon dioxide + water
(Combustion)
KClO3
potassium chlorate
(Decomposition)
 KCl + O2
 potassium chloride + oxygen
Pb(NO3)2 + KI  (oops…duplicate question – see above)
HCl + NaOH
 NaCl + H2O
hydrochloric acid + sodium hydroxide  sodium chloride + water
(Acid-base neutralization)
CaO + 2 HNO3
 Ca(NO3)2 + H2O
calcium oxide + nitric acid
 calcium nitrate + water
(Acid-base neutralization – note: CaO is a base)
Na2CO3 + Mg(NO3)2
 2 NaNO3 + MgCO3
sodium carbonate + magnesium nitrate  sodium nitrate + magnesium carbonate
(Double displacement)
copper (II) chloride is added to magnesium bicarbonate  copper (II) bicarbonate + magnesium chloride
CuCl2 + Mg(HCO3)2
 Cu(HCO3)2 + MgCl2
(Double displacement)
lead (II) nitrate is added to potassium iodide  (duplicate question… I really like this question obviously!)
3 KOH + H3PO4
 K3PO4 + 3 H2O
potassium hydroxide + phosphoric acid  potassium phosphate + water
(Acid-base neutralization)
CaCl2 + F2
Calcium chloride + Fluorine
(Single displacement)
 CaF2 + Cl2
 calcium fluoride + chlorine
calcium hydroxide +phosphoric acid  calcium phosphate + water
3 Ca(OH)2 + 2 H3PO4
 Ca3(PO4)2 + H2O
(Acid-base neutralization)
sodium phosphate is added to calcium nitrate  sodium nitrate + calcium phosphate
2 Na3PO4 + 3 Ca(NO3)2
 6 NaNO3 + Ca3(PO4)2
(Double displacement)
silver nitrate is added to sodium hydroxide
AgNO3 + NaOH
(Double displacement)
 sodium nitrate + silver hydroxide
 NaNO3 + AgOH
ammonium hydroxide is added to sulfuric acid ammonium sulfate + water
2 NH4OH + H2SO4
 (NH4)2SO4 + 2 H2O
(Acid-base neutralization)
2 Cu + O2  2 CuO
copper + oxygen  copper (II) oxide
(Combustion)
3 Cu(OH)2 + 2 H3PO4
 Cu3(PO4)2 + 6 H2O
copper (II) hydroxide + phosphoric acid  copper (II) phosphate + water
(Acid-base neutralization)
Fe(NO3)3 + 3 AgCl
 FeCl3 + 3 AgNO3
Iron (III) nitrate + silver chloride Iron (III) chloride + silver nitrate
(Double displacement)
KClO3
 KCl + O2
potassium chlorate  potassium chloride + oxygen
(Decomposition)
2. A small jug containing phosphoric acid was spilled in the lab room. You needed to clean up the mess
quickly and checked the chemistry storage unit where you saw three other jugs available:
Sodium chloride (aq)
Potassium hydroxide (aq)
Hydrosulfuric acid (aq)
Which solution can you use to clean up your spill? Potassium hydroxide
Why did you pick this solution? Because potassium hydroxide is a base. (Remember that base will
neutralize acid, producing salt & water as the products.)
Write the balanced chemical equation showing both reactants and products of this reaction.
Phosphoric acid + potassium hydroxide  potassium phosphate + water
H3PO4 + 3 KOH  K3PO4 + 3 H2O