2. INORGANIC CHEMISTRY
A – Group 1 (Alkali Metals) – Lithium, Sodium and Potassium:
2.1 – understand how the similarities in the reactions of these elements with water provide evidence for
their recognition as a family of elements
o They all have similar characteristics due to the single electron in the outer shell
o All of the metals in group 1 react vigorously with water
o Word Equation: metal + water metal hydroxide + hydrogen
2.2 – understand how the differences between the reactions of these elements with air and water provide
evidence for the trend in reactivity in Group 1
o Lithium = fizzes steadily (HYDROGEN IS PRODUCED)
o Sodium = melts into a ball then fizzes quickly floats across the water
o Potassium = gives off sparks and hydrogen burns with a lilac flame
2.3 – use knowledge of trends in Group 1 to predict the properties of other alkali metals
Going down the group:
o More reactive lithium takes longer to react caesium explodes (most reactive)
o Melting point decreases
1D = Group 1
2.4 – explain the trend in reactivity in Group 1 in terms of electronic configurations reactivity
Going down the group: increases, going
down the group
o Easier to lose electrons due to increase in electron shells outer electron further
o More electron shielding decrease in attraction between the positively charged nucleus and negatively
charged outer shell electrons lost easier easier to form positive metal ions (cations)
B – Group 7 (Halogens) – Chlorine, Bromine and Iodine:
2.5 – know the colours, physical states (at room temp) and trends in physical properties of these elements
o Chlorine: fairly reactive + poisonous yellow-green gas boiling point = -34 ̊ atomic number = 17
o Bromine: red-brown liquid lets off orange vapour at room temp. boiling point = 59 ̊ atomic number = 35
o Iodine = dark grey solid gives off purple vapour when heated boiling point = 185 ̊ atomic number = 53
2.6 – use knowledge of trend in Group 7 to predict the properties of other halogens
7UP = Group 7
Going down the group: reactivity
increases,
o Less reactive fluorine = most reactive oBigger atoms = less reactive
going up the
o Trend in state from gas liquid solid oBoiling + melting point increases
group
o Higher relative molecular mass oColour of elements get darker
2.7 – understand how displacement reactions involving halogens and halides provide evidence in reactivity
in Group 7
o A more reactive halogen can displace a less reactive
o More reactive metal = greater change in temperature than a less reactive metal
o E.g. Chlorine will displace bromine if you bubble the gas through a solution of potassium bromide
o Chlorine + Potassium Bromide Potassium Chloride + Bromine
o When a halogen is in a compound, it forms a halide Chlorine = above bromine so
o Chlorine/Bromine = halogen Chloride/Bromide = halide chlorine takes the place of bromine
, 2. INORGANIC CHEMISTRY
2.8 – explain the trend in reactivity in Group 7 in terms of electronic configurations
o Halogens react by gaining an electron in their outer shell
1. Outer shell becomes further from the nucleus
2. Electron shielding increases
3. Attraction between nucleus and outer electron decreases
4. Electrons are gained less easily
5. Halogens become less reactive
C – Gases in the Atmosphere:
2.9 – know the approximate percentages by volume of the four most abundant gases in dry air
Gas Formula E/C A/M % Properties Uses
Nitrogen N2 Element Molecule 78 Unreactive Food packets, fertilisers
Oxygen O2 Element Molecule 21 Very reactive Respiration, combustion
Argon Ar Element Atom 0.9 Very unreactive Coloured lights, air ships
Carbon dioxide CO2 Compound Molecule 0.04 Unreactive PS, fizzy drinks
Water vapour H2O Compound Molecule 0.063 Respiration
2.10 – understand how to determine the percentage by volume of oxygen in air using experiments involving
the reactions of metals (e.g. iron) and non-metals (e.g. phosphorus) with air
Iron:
o The iron reacts with the oxygen (rusting)
1. Soak some iron wood in acetic acid (catalyse the reaction) and push the wool
into a measuring cylinder
2. Invert the measuring cylinder into a beaker of water
3. Record the starting position of the water in the cylinder
4. Over time, the water will rise up in the cylinder (this is because the iron
reacts with oxygen to make iron oxide, the water rises to fil up space from the oxygen)
5. Leave for a week or until the water no longer rises
6. Record the end position of the water in the cylinder
7. Find the percentage change (should be around 20% - the
percentage of oxygen in dry air)
o Heavier/lighter mass of iron after the experiment? Heavier – the oxygen atoms add more weight onto the iron
atoms
Phosphorus/Copper:
1. Place copper in a tube with syringes at either end – make
sure one syringe is filled with air
2. Heat the copper and use the syringes to pass oxygen across
the middle
3. The copper will react with oxygen to make copper oxide
4. As it react the amount of air in the syringes will decrease
5. Leave the gas to cool before recording the volumes
6. Measure the starting and ending volume of air in one of the syringe (push all the air into one of the syringes)
7. Find the percentage change (should be around 20% - the percentage of oxygen in dry air)
o How to tell if reaction is finished? Volume on syringes remains constant and copper changes from pinky brown to
black
o Why was the gas left for a few minutes in step 5? Gases expand when hot cooling down = allows them to
contract
A – Group 1 (Alkali Metals) – Lithium, Sodium and Potassium:
2.1 – understand how the similarities in the reactions of these elements with water provide evidence for
their recognition as a family of elements
o They all have similar characteristics due to the single electron in the outer shell
o All of the metals in group 1 react vigorously with water
o Word Equation: metal + water metal hydroxide + hydrogen
2.2 – understand how the differences between the reactions of these elements with air and water provide
evidence for the trend in reactivity in Group 1
o Lithium = fizzes steadily (HYDROGEN IS PRODUCED)
o Sodium = melts into a ball then fizzes quickly floats across the water
o Potassium = gives off sparks and hydrogen burns with a lilac flame
2.3 – use knowledge of trends in Group 1 to predict the properties of other alkali metals
Going down the group:
o More reactive lithium takes longer to react caesium explodes (most reactive)
o Melting point decreases
1D = Group 1
2.4 – explain the trend in reactivity in Group 1 in terms of electronic configurations reactivity
Going down the group: increases, going
down the group
o Easier to lose electrons due to increase in electron shells outer electron further
o More electron shielding decrease in attraction between the positively charged nucleus and negatively
charged outer shell electrons lost easier easier to form positive metal ions (cations)
B – Group 7 (Halogens) – Chlorine, Bromine and Iodine:
2.5 – know the colours, physical states (at room temp) and trends in physical properties of these elements
o Chlorine: fairly reactive + poisonous yellow-green gas boiling point = -34 ̊ atomic number = 17
o Bromine: red-brown liquid lets off orange vapour at room temp. boiling point = 59 ̊ atomic number = 35
o Iodine = dark grey solid gives off purple vapour when heated boiling point = 185 ̊ atomic number = 53
2.6 – use knowledge of trend in Group 7 to predict the properties of other halogens
7UP = Group 7
Going down the group: reactivity
increases,
o Less reactive fluorine = most reactive oBigger atoms = less reactive
going up the
o Trend in state from gas liquid solid oBoiling + melting point increases
group
o Higher relative molecular mass oColour of elements get darker
2.7 – understand how displacement reactions involving halogens and halides provide evidence in reactivity
in Group 7
o A more reactive halogen can displace a less reactive
o More reactive metal = greater change in temperature than a less reactive metal
o E.g. Chlorine will displace bromine if you bubble the gas through a solution of potassium bromide
o Chlorine + Potassium Bromide Potassium Chloride + Bromine
o When a halogen is in a compound, it forms a halide Chlorine = above bromine so
o Chlorine/Bromine = halogen Chloride/Bromide = halide chlorine takes the place of bromine
, 2. INORGANIC CHEMISTRY
2.8 – explain the trend in reactivity in Group 7 in terms of electronic configurations
o Halogens react by gaining an electron in their outer shell
1. Outer shell becomes further from the nucleus
2. Electron shielding increases
3. Attraction between nucleus and outer electron decreases
4. Electrons are gained less easily
5. Halogens become less reactive
C – Gases in the Atmosphere:
2.9 – know the approximate percentages by volume of the four most abundant gases in dry air
Gas Formula E/C A/M % Properties Uses
Nitrogen N2 Element Molecule 78 Unreactive Food packets, fertilisers
Oxygen O2 Element Molecule 21 Very reactive Respiration, combustion
Argon Ar Element Atom 0.9 Very unreactive Coloured lights, air ships
Carbon dioxide CO2 Compound Molecule 0.04 Unreactive PS, fizzy drinks
Water vapour H2O Compound Molecule 0.063 Respiration
2.10 – understand how to determine the percentage by volume of oxygen in air using experiments involving
the reactions of metals (e.g. iron) and non-metals (e.g. phosphorus) with air
Iron:
o The iron reacts with the oxygen (rusting)
1. Soak some iron wood in acetic acid (catalyse the reaction) and push the wool
into a measuring cylinder
2. Invert the measuring cylinder into a beaker of water
3. Record the starting position of the water in the cylinder
4. Over time, the water will rise up in the cylinder (this is because the iron
reacts with oxygen to make iron oxide, the water rises to fil up space from the oxygen)
5. Leave for a week or until the water no longer rises
6. Record the end position of the water in the cylinder
7. Find the percentage change (should be around 20% - the
percentage of oxygen in dry air)
o Heavier/lighter mass of iron after the experiment? Heavier – the oxygen atoms add more weight onto the iron
atoms
Phosphorus/Copper:
1. Place copper in a tube with syringes at either end – make
sure one syringe is filled with air
2. Heat the copper and use the syringes to pass oxygen across
the middle
3. The copper will react with oxygen to make copper oxide
4. As it react the amount of air in the syringes will decrease
5. Leave the gas to cool before recording the volumes
6. Measure the starting and ending volume of air in one of the syringe (push all the air into one of the syringes)
7. Find the percentage change (should be around 20% - the percentage of oxygen in dry air)
o How to tell if reaction is finished? Volume on syringes remains constant and copper changes from pinky brown to
black
o Why was the gas left for a few minutes in step 5? Gases expand when hot cooling down = allows them to
contract
