Chemical formula • Represent chemical compound • Show elements present in compound

Name compound

Chemical Formula

Name of each element

Sulphuric acid H2SO4 2 Hydrogen, 1 Sulphur, 4 Oxygen

Ammonia NH3 1 Nitrogen, 3 Hydrogen

Hydrogen Chloride HCI 1 Hydrogen, 1 Chlorine

Nitric Acid HNO3 1 Hydrogen, 1 Nitrogen, 3 Oxygen

Empirical formula • Represent simplest whole number ratio of atoms of the elements • Formula obtain by experiment

Molecular formula • Represent actual number atoms of elements that combine to form compound

Structural formula • Represent arrangement of atoms in a compound

Chemical Compound Ethene

C1H1

C2H2

Video tutorial on Molecular/empirical formula

Khan Academy

Chemical Reaction

Word equation

CaCO3 (s) + 2HCI(aq) → CaCI2(aq) + CO2(g) + H2O(l)

Physical states + symbols (s) – solid (I) - liqud (g) – gas (aq) – aqueous ∆ - heating ppt – precipitate/solid ↔ - reversible

Calcium + hydrochloric → Calcium + carbon + water carbonate acid chloride dioxide

Reaction Stoichiometry • Quantitative relationship bet quantities of reactants/ products • Used to determine quantities/amt in (mass, moles, volume) • Predicts amt reactants react and amt products formed • Chemical reaction react in definite ratios

Chemical equation

Molecular equation

1CaCO3(s) + 2HCI(aq) → 1CaCI2(aq) + 1CO2(g) + 1H2O(l)

Reactants – Left side Products – Right side

Conservation Mass Total Mass reactants = Total Mass products

Mole Ratio (stoichiometric ratio) Coefficient in front of reactants/products - moles

1 : 2 → 1 : 1 : 2

Video on conservation mass

Before After

Chemical reaction • Matter is neither created nor destroyed • Undergoes physical and chemical change. • LAW of conservation of mass.

Chemical Reaction

Word equation

Chemical equation

Molecular equation

Reactants – Left side Products – Right side

Conservation Mass Total Mass reactants = Total Mass products

Mole Ratio (stoichiometric ratio) Coefficient in front of reactants/products - moles

Lead + Potassium → Lead + Potassium Nitrate iodide iodide nitrate

1Pb(NO3)2(aq) + 2KI(aq) → 1PbI2(s) + 2KNO3(aq)

1Pb(NO3)2(aq) + 2KI(aq) → 1PbI2(s) + 2KNO3(aq)

Mass of reactants (PbNO3 + KI) = 15.82

Mass of products (PbI3 + KNO3) = 15.82

After Before

Video on conservation mass 1 : 2 → 1 : 2

2H2 + 2I2 → 4HI 3NO2 + 3NO2 → 3N2O4

4g H2 508g I2 512g HI 150g NO2 300g N2O4

Simulation on conservation mass/balancing equation

Click to view animation

+

2 moles H2 2 moles I2 4 moles HI

Simulation on Chembalancer

150g NO2

3 moles NO2 3 moles NO2 3 moles N2O4

+ + +

Cations/Metals/+ve ions

Gp 1 Gp 2 Gp 3 Transition metals ions ( variable oxidation states)

Oxidation state

+1

Oxidation

state

+2

Oxidation state

+3

Sc +3

Ti +2 +3

V +2 +3

Cr +2 +3 +6

Mn +2 +3 +6 +7

Fe +2 +3

Co +2 +3

Ni +2

Cu +1 +2

Zn +2

Li 1+ Be2+ Sc 3+ Ti 2+

Ti 3+

V 2+

V 3+

Cr 2+

C r3+

Cr6+

Mn 2+

Mn 3+

Mn 6+

Mn 7+

Fe 2+

Fe 3+

Co2+

Co 3+

Ni2+ Cu1+

Cu2+

Zn2+

Na 1+ Mg2+ Al 3+

K 1+ Ca2+

Anion/Non metal

Gp 5 Gp 6 Gp 7

Oxidation state

Oxidation state

Oxidation state

-3 -2 -1

N3- O2- F-1

P3- S2- CI-1

Br-1

I-1

Metal/Cations/+ve ions

Non Metal/ Anions/ -ve ions

Ionic Compound

Li2O MgCI2 Al2O3 FeO Iron(II) oxide

NiO Nickel(II) oxide

CuO Copper(II) oxide

Li3N Mg3N2 AlN Fe3N2

Iron(II) nitride Ni3N2

Nickel(II) nitride Cu3N2

Copper(II) nitride

Oxidation state/Charge ion → Li1+ O2-

Formula compound Li

2 O

1

Video on polyatomic ions

Writing Chemical Formula

Step 1 : Write Oxidation state/charge

Step 2 : Balance it, (electrically neutral)

by cross multiply – as subscript

Polyatomic ions

Group of non-metals bonded together

Oxidation state

Oxidation state

Oxidation state

-1/+1 -2 -3

(OH)-1

Hydroxide (SO4)2-

Sulphate (PO4)3-

Phosphate

(CN)-1

Cyanide (SO3)2-

Sulphite

(SCN)-1

Thiocyanate (CO3)2-

Carbonate

(NO3)-1

Nitrate (S2O3)2-

Thiosulphate

(NO2)-1

Nitrite (Cr2O7)2-

Dichromate

(NH4)+1

Ammonium

Polyatomic ions

Li2(CO3) Mg(CO3) Al2(CO3)3 Fe(CO3) Ni(CO3) Cu(CO3)

Li(OH) Mg(OH)2 Al(OH)3 Fe(OH)2 Ni(OH)2 Cu(OH)2

Li2(SO4) Mg(SO4) Al2(SO4)3 FeSO4 Ni(SO4) Cu(SO4) Video on polyatomic ions

Ionic Compound

Writing Chemical Formula

Metal/Cations/+ve ions

Cations/Metals/+ve ions

Gp 1 Gp 2 Gp3 Transition metals ions ( variable oxidation states)

Oxidation state

+1

Oxidation state

+2

Oxidation state

+3

Sc +3

Ti +2 +3

V +2 +3

Cr +2 +3 +6

Mn +2 +3 +6 +7

Fe +2 +3

Co +2 +3

Ni +2

Cu +1 +2

Li 1+ Be2+ Sc 3+ Ti 2+

Ti 3+

V 2+

V 3+

Cr 2+

C r3+

Cr6+

Mn 2+

Mn 3+

Mn 6+

Mn 7+

Fe 2+

Fe 3+

Co2+

Co3+

Ni2+ Cu1+

Cu2+

Na 1+ Mg2+ Al 3+

K 1+ Ca2+

Oxidation state/Charge ion→ Li1+ (CO3)2-

Formula compound Li

2 (CO

3)1

Step 1 : Write Oxidation state/charge ion

Step 2 : Balance it, (electrically neutral)

by cross multiply – as subscript

Acids Alkali Metal Hydroxide

Metal oxides Salts Gas

HCI Hydrochloric acid

KOH Potassium hydroxide

CuO Copper(II) oxide

CaCO3

Calcium carbonate CO

Carbon monoxide

HNO3

Nitric acid NaOH

Sodium hydroxide MgO

Magnesium oxide Na2CO3

Sodium carbonate CO2

Carbon dioxide

H2SO3

Sulphurous acid Ca(OH)2

Calcium Hydroxide ZnO

Zinc oxide NaHCO3

Sodium bicarbonate SO2

Sulphur dioxide

HCOOH Methanoic acid

NH3

Ammonia Na2O

Sodium oxide KNO3

Potassium nitrate SO3

Sulphur trioxide

CH3COOH Ethanoic acid

Mg(OH)2

Magnesium hydroxide Al2O3

Aluminium oxide Pb(NO3)2

Lead (II) Nitrate NO2

Nitrogen dioxide

H3PO4

Phosphoric acid Cu(OH)2

Copper (II) hydroxide Fe2O3

Iron(III) oxide NaNO3

Sodium nitrate CH4

Methane

H2CO3

Carbonic acid Al(OH)3

Aluminium hydroxide K2S

Potassium sulphide PbI2

Lead (II) nitrate H2S

Hydrogen sulphide

HNO2

Nitrous acid Fe(OH)2

Iron (II) hydroxide PbS

Lead(II) sulphide AgCI

Silver chloride O2

Oxygen

HF Hydrofluoric acid

Fe(OH)3

Iron (III) hydroxide ZnS

Zinc sulphide MgSO4

Magnesium sulphate N2

Nitrogen

HCIO Hypochlorous acid

Zn(OH)2

Zinc hydroxide AI2S3

Aluminium sulphide Na2S2O3

Sodium thiosulphate CI2

Chlorine

Chemical Formula for common chemicals

Naming chemical compound Writing chemical formula Writing chemical formula

VIDEO TUTORIALS

Chemical Equation

Chemical Reaction/Change

Complete ionic equation

Molecular equation

Net ionic equation

1Pb(NO3)2(aq) + 2NaCI(aq) → 1PbCI2(s) + 2NaNO3(aq)

1Pb2+(aq) + 2NO3

-(aq) + 2Na+

(aq) + 2CI-(aq) → 1PbCI2(s) + 2Na+

(aq) + 2NO3-(aq)

Molecular equation

Complete ionic

equation

Net ionic equation

unchanged

1Pb2+(aq) + 2CI-

(aq) → 1PbCI2(s)

1Pb2+(aq) + 2NO3

-(aq) + 2Na+

(aq) + 2CI-(aq) → 1PbCI2(s )+ 2Na+

(aq) + 2NO3-(aq)

Break

aq → ions

Break

aq → ions

Break

aq → ions

Cancel out Cancel out

Video on ionic equation

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

• Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

Chemical Equation

Chemical Reaction/Change

Complete ionic equation

Molecular equation

Net ionic equation

Molecular equation

Complete ionic

equation

Net ionic equation

unchanged Break

aq → ions

Break

aq → ions Break

aq → ions

Cancel out Cancel out

Na2CO3(aq) + 2HNO3(aq) → 2NaNO3(aq) + H2O(l) + CO2(g)

2Na+(aq) + CO3

2-(aq) + 2H+

(aq) + 2NO3-(aq) → 2Na+

(aq) + 2NO3-(aq) + H2O(l) + CO2 (g)

CO32-

(aq) + 2H+(aq) → H2O(l) + CO2(g)

2Na+(aq) + CO3

2-(aq) + 2H+

(aq) + 2NO3-(aq) → 2Na+

(aq) + 2NO3-(aq) + H2O(l) + CO2 (g)

•Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

Click here for extra notes Click for here questions and answers to ionic equation Great link to simulation on stoichiometry. Click here.

Chemical Equation

Chemical Reaction/Change

Complete ionic equation

Molecular equation

Net ionic equation

•Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

Molecular equation

Complete ionic

equation

Net ionic equation

unchanged Break

aq → ions

Break

aq → ions

Break

aq → ions

Cancel out Cancel out

2 Na3PO4(aq) + 3CaCI2(aq) → 6NaCI(aq) + Ca3(PO4)2(s)

6Na+(aq) + 2PO4

3-(aq) + 3Ca2

(aq) + 6CI-(aq) → 6Na+

(aq) + 6CI-(aq) + Ca3(PO4)2(s)

2PO43-

(aq) + 3Ca2+(aq) → Ca3(PO4)2(s)

6Na+(aq) + 2PO4

3-(aq) + 3Ca2

(aq) + 6CI-(aq) → 6Na+

(aq) + 6CI-(aq) + Ca3(PO4)2(s)

Click here for extra notes Click for here questions and answers to ionic equation Great link to simulation on stoichiometry. Click here.

Molecular equation

Complete ionic

equation

Net ionic equation

Cancel out Cancel out

Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

Zn(s) + Cu2+(aq) + SO4

2- (aq) → Zn2+

(aq) + SO42-

(aq) + Cu(s)

Zn (s) + Cu2+(aq) → Zn2+

(aq) + Cu(s)

Zn(s) + Cu2+(aq) + SO4

2- (aq) → Zn2+

(aq) + SO42-

(aq) + Cu(s)

Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

Mg(s) + 2H+(aq) + 2Cl-

(aq) → Mg2+(aq) + 2Cl-

(aq) + H2(g)

Mg(s) + 2H+(aq) + 2Cl-

(aq) → Mg2+(aq) + 2Cl-

(aq) + H2(g)

Mg(s) + 2H+(aq) → Mg2+

(aq) + H2(g)

Molecular equation

Complete ionic

equation

Net ionic equation

Cancel out Cancel out

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

• Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

•Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

Ionic Equation

Molecular equation

Complete ionic

equation

Net ionic equation

Cancel out Cancel out

Molecular equation

Complete ionic

equation

Net ionic equation

K2SO4(aq) + BaCl2 (aq) → BaSO4(s) + 2KCl(aq)

2K+(aq) + SO4

2-(aq) + Ba2+

(aq) + 2Cl-(aq) → BaSO4(s) + 2K+

(aq) + 2Cl-(aq)

2K+(aq) + SO4

2-(aq) + Ba2+

(aq) + 2Cl-(aq) → BaSO4(s) + 2K+

(aq) + 2Cl-(aq)

SO42-

(aq) + Ba2+(aq) → BaSO4 (s)

2Na+(aq) + 2OH-

(aq) + 2H+(aq) + SO4

2-(aq) → 2Na+

(aq) + SO42-

(aq) + 2H2O(l)

2NaOH(aq) + H2SO4 (aq) → Na2SO4(aq) + 2H2O(l)

2Na+(aq) + 2OH-

(aq) + 2H+(aq) + SO4

2-(aq) → 2Na+

(aq) + SO42-

(aq) + 2H2O(l)

2OH-(aq) + 2H+

(aq) → 2H2O(l)

OH-(aq) + H+

(aq) → H2O(l)

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

•Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

•Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

Cancel out Cancel out

Ionic Equation

Molecular equation

Complete ionic

equation

Net ionic equation

Cancel out Cancel out

Molecular equation

Complete ionic

equation

Net ionic equation

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

• Spectators ions- don’t participate in rxn • Cancel out ions from both sides of eqn • Only ions involved in rxn

•Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

•Break down electrolytes, (aq) → ions • Leave solid, liquid, gas unchanged

3(NH4)2CO3(aq) + 2Al(NO3)3(aq) → 6NH4NO3(aq) + Al2(CO3)3(s)

6NH4+

(aq) + 3CO32-

(aq) + 2Al3+(aq) + 6NO3

-(aq) → 6NH4

+(aq) + 6NO3

-(aq) + Al2(CO3)3(s)

6NH4+

(aq) + 3CO32-

(aq) + 2Al3+(aq) + 6NO3

-(aq) → 6NH4

+(aq) + 6NO3

-(aq) + Al2(CO3)3(s)

3CO32-

(aq) + 2Al3+(aq) → Al2(CO3)3(s)

CaCl2 (aq) + Na2CO3(aq) → 2 NaCl(aq) + CaCO3(s)

Ca2+(aq)+ 2 Cl- (aq) + 2 Na+ (aq)+ CO3

2- (aq) -> 2 Na+(aq) + 2Cl-

(aq) + CaCO3 (s)

Ca2+(aq)+ 2Cl-

(aq) + 2Na+(aq)+ CO3

2-(aq) → 2Na+

(aq) + 2Cl-(aq) + CaCO3 (s)

Ca2+(aq) + CO3

2-(aq) → CaCO3 (s)

Ionic Equation

Cancel out Cancel out

1Pb(NO3)2(s) + 2KI(aq) → 1PbI2(s) + 2KNO3 (aq)

Balanced Chemical equation

Coefficient • Mole proportion/ratio •(reactant) → (product) 1 : 2 → 1 : 2

Concept Map

Chemical Reaction

Chemical Equation

Molecular Equation

Complete Ionic Equation

Net Ionic Equation

1Pb2+(aq) + 2NO3

-(aq) + 2K+

(aq) + 2I-(aq) → 1PbI2(s) + 2K+

(aq) + 2 NO3-(aq)

1Pb2+(aq) + 2CI-

(aq) → 1PbCI2(s)

Chemical Change

leads to

represented by

1Pb(NO3)2(s) + 2KI(aq) → 1PbI2(s) + 2KNO3 (aq)

Stoichiometry • Quantitative relationship bet quantities of reactants/products • Determine quantities/amt in (mass, moles, volume) • Predicts amt reactants react and amt products formed • Chemical rxn reacts in definite ratios

Video on concept map above Simulation on stoichiometry Simulation on chembalancer

Exercise

Write balanced equation for the following reactions 1. Reaction of sulphur dioxide and oxygen to form sulphur trioxide 2SO2(g) + O2(g) → 2SO3(g)

2. Neutralization between potassium hydroxide and sulphuric acid to form potassium sulphate and water 2KOH(aq) + H2SO4(aq) → K2SO4(aq) + 2H2O(I)

3. Combustion of ethane (C2H6) in air to form carbon dioxide and water 2C2H6(g) + 7O2(g ) → 4CO2(g) + 6H2O(I)

4. Displacement reaction between zinc metal and copper(II) sulphate solution to form copper metal and zinc sulphate Zn(s) + CuSO4(aq) → Cu(s) + ZnSO4(aq)

5. Decomposition of zinc carbonate to form zinc oxide and carbon dioxide when heated ZnCO3(s) → ZnO(s) + CO2(g)

6. Ammonia reacting with oxygen to form nitrogen monoxide and water. 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(I)

7. Manganese(IV) oxide reacting with hydrochloric acid to form manganese(II) chloride solution, chlorine and water MnO2(s) + 4HCI(aq) → MnCI2(aq) + CI2(g) + 2H2O(I)

8. Neutralization between aqueous ammonia with hydrochloric acid to form ammonium chloride and water. NH4OH(aq) + HCI(aq) → NH4CI(aq) + H2O(I)