1. Atoms of different elements combine to form compounds by the formation of new chemical bonds
Describe how the transfer of electrons produces cations and anions, which forms ionic bonds
Describe an ion as an atom or group of atoms with a positive or negative charge
Describe the formation of sodium ions, Na1+, and chloride ions,
Cl1-
Metal elements combine with non metal elements to form a strong ionic bond.
Elements either lose or gain e- in order to form a stable ion. Stability means a full outer shell.
Elements from the LHS of the PT form +ive ions, as they give e-. Whereas elements from the RHS of the PT form –ive ions, as they take e-.
Na is in Gp 1 and therefore gives 1 e- away to form a stable ion. Cl is in Gp 7 and therefore takes 1 e- from Na, in order to form a stable outer shell.
What do the endings –ide and –ate in the names of compounds mean?
Write the formulae of ionic compounds.
Elements in groups 1, 2, 6 & 7 all form ionic bonds
Name
Formulas
Oxides (O)
CuO, Fe2O3, KO
Hydroxides (OH)
NaOH, KOH
Halides (Gp 7 elements)
NaCl, KBr,
Nitrates (NO3)
NaNO3, KNO3
Carbonates (CO3)
NaCO3,
Sulfates (SO4)
NaSO4, CuSO4
Except for H and He, who only have 1 shell, with a maximum of 2 e-. Elements in Gp 1, give 1e- away to form a 1+ charge. Gp 2 give 2 e- away to form a 2+ charge. Elements in Gp 3, give 3 e- away to form a 3+ charge.
Elements in Gp 5, take 3e- to form a 1- charge. Gp 2 take 2 e- to form a 2- charge. Elements in Gp 7, take 3 e- to form a 1- charge.
Ide means a Halide ion (they have taken 1 e- to form a -ive charge) (Flouride, Chloride, Bromide & Iodide)
Ate means either 3 or 4 oxygens attached (Sulphate (SO4) (Carbonate CO3)

2. What do ionic compounds look like?
What are the properties of ionic compounds?
Ionic compounds form a lattice structure, in a regular arrangement. The ions are held together by their +ive and –ive charges. The ionic bond is very strong
1) They have high melting and boiling points.
2) They do not conduct electricity as solids.
3) They do conduct electricity, when they are molten (liquid hot, melted) and in aqueous solution (in water)
Explain the solubility rules of ionic compounds.
What are precipitates?
Predict whether a precipitate is formed.
Soluble
Insoluble
Na, K, NH3,
Pb, Ba & Ca
NaCl, KCl, NH3Cl, all other Cl
PbCl2, BaCl2, CaCl2, AgCl2
NaNO3, KNO3, NH3NO3
all other NO3
Pb(NO3)2, Ba(NO3)2, Ca(NO3)2
NaSO4, KSO4, (NH3)2SO4
all other SO4
PbSO4, BaSO4, CaSO4
NaCO3, KCO3, (NH3)2CO3,
PbCO3, BaCO3, CaCO3, all other CO3
NaOH, KOH, NH3OH
Pb(OH)2, Ba(OH)2, Ca(OH)2 all other OH
Precipitates are all the insoluble ionic compounds (salts). In a reaction of solutions, look for the insoluble salt.
Pb(NO3)2 + 2NaOH 
Pb(OH) NaNO3
AgNO3 + NaCl  AgCl + NaNO3
2NaOH + MgCl2 → 2NaCl  + Mg(OH)2
Fe(NO3)3 + 3NaOH → Fe(OH) NaNO3

3. Which ions could be present if the precipitate formed with NaOH is:
Describe tests to show the following ions:
Describe tests to show the following precipitates:
How is barium sulphate (BaSO4) used in medicine?
Describe tests to show the following ions:
Ion
Test
Na+
Flame test: Yellow K+
Flame test: Lilac
Ca2+
Flame test: Red
Cu2+
Flame test: Green-Blue
CO32+
Add dilute acid and identifying the CO2. CO2 turns limewater milky.
Ion
Test
SO32-
Add BaCl  white precipitate of BaSO3
SO42-
Add BaCl  white precipitate of BaSO4
To distinguish between sulfite (SO3) and sulphate (SO4), do a secondary test. Add HCl to both the white precipitates. barium sulfite dissolves, whereas
barium sulfate does not dissolve.
Ion
Test
Cl-
Add AgNO3  AgCl white
Br-
Add AgNO3  AgBr cream I-
Add AgNO3  IBr yellow
SO2
Add HCl  turns damp chromate paper, green
Ca2+
White
Mg2+
Cu(II)2+
Blue
Fe(II)2+
Dirty Green
Fe(III)3+
Reddish Brown
Al3+
White at first, then turns colourless when NaOH is added
NH4+
No precipitate, but an escaping gas turns damp red litmus paper, blue.
It is given as a ‘barium meal’ to X-ray patients because:
a) it is opaque to X-rays
b) it is safe to use as, although barium salts are toxic, its insolubility prevents it entering the blood.
Name the precipitate formed when NaOH reacts with
Which ions could be present if the precipitate formed with NaOH is:
a) Brown
 Iron 3
b) White
Chloride, Calcium, Magnesium or Aluminium
What would you see if NaOH solution was added to a solution of:
a) Cu2+ ions
 Cu(OH)2 = insoluble
Blue precipitate
b) Fe2+ ions
Fe(OH)2 = insoluble
Green precipitate
a) Al(NO3)3
Aluminium hydroxide
b) Ca(NO3)2
Calcium hydroxide

4. What is meant by lattice structure.
Sodium chloride is soluble in water, but magnesium oxide is insoluble in water. Under what conditions will: a sodium chloride conduct electricity? b magnesium oxide conduct electricity?
Suggest why magnesium oxide blocks are used to line the inside of blast furnaces, which produce molten iron.
Substance X melts at 1530 °C and conducts electricity when solid. Explain why it is not an ionic compound.
Substance Y melts at 373 °C. Describe a simple test you could do to see if it is an ionic compound.
Melt substance Y and then connect it up to a circuit with a bulb and see if electricity pass through it to light the bulb.
Magnesium oxide is an ionic compound and therefore has high melting point.
a) Dissolve sodium chloride in water to make it aqueous.
b) Melt magnesium oxide to make it molten.
Ionic compounds only conduct electricity when either in an aqueous state or when molten.
Give the formulae for:
a sodium oxide
NaO
b magnesium chloride
MgCl2
For each of the following compounds, give the symbols of the ions it contains and its formula:
a potassium chloride
Na+Cl-
b magnesium oxide
Mg2+O2-
c aluminium hydroxide
Al3+(OH-)3
Phosphide ions are P3−. Give the correct charges and write the correct formula for:
a aluminium phosphide
Al3+P3-
What is meant by lattice structure.
Lattice structure is the regular arrangement of ions in an ionic compound. The ions are held together by a strong ionic bond formed between the opposing charges of +ive and –ive ions.