Inorganic Chemistry and the Periodic Table Flashcards
Explain the trend in Ionisation Energies down Group 2
- Ionisation Energies Decreases
- Down the group number of shells increase
- The positive charge nucleus is increased as you go down the Group but is counter affected by increase shielding
- Overall This will lead to a greater distance from a nucleus weakening electrostatic attraction
Explain the trend in Reactivity down Group 2
Reactivity increases
Ionisation Energy decreases as you go down the group
Lower activation energies
Outer two electrons can form +2 ions more easily/quicker in reactions
What is formed if a Group 2 metal reacts with oxygen
Solid white Metal oxide
What is formed if a Group 2 metal reacts with water
Metal hydroxide
Hydrogen
What is formed if a Group 2 metal reacts with chlorine
White Solid Chloride
What is the flame colour for lithium
Red
What is the flame colour for sodium
Yellow
What is the flame colour for potassium
Lilac
What is the flame colour for beryllium
No flame colour
What is the flame colour for calcium
Brick Red
What is the flame colour for Strontium
Red
What is the flame colour for Barium
Apple Green
What is formed if a Group 2 metal oxide reacts with water
Metal hydroxides which dissolve making strongly alkaline solutions
Except Beryllium oxide
What is formed if a Group 2 metal hydroxide reacts with oxygen
Metal hydroxides
What is formed if a Group 2 metal oxide reacts with a dilute acid
Salt
Water
What is formed if a Group 2 metal hydroxide reacts with a dilute acid
Salt
Water
Describe the trend in solubility of hydroxides
Solubility increases as you go down the group
Describe the trend in solubility of sulphates
Solubility decreases as you go down the group
Define ‘Thermal Decomposition’
Thermal Decomposition is when a substance breaks down when it is heated
Define ‘Thermal Stability’
An indication of how easily a compound thermally decomposes.
Explain the thermal stability of Group 1 Nitrates and Carbonates com[pared with Group 2
Group 1 Nitrates and Carbonates more more thermally stable than Group 2
- Smaller ionic charge
- Less distortion
- Weaker polarising power
Explain the trend in thermal stability of Group 2 Nitrates and Carbonates
Thermal Stability increases down Group 2
- Size of Charge remains the same but Ionic radius increases so charge density decreases
- leading to lower polarising power
- distorts the anions(nitrate/carbonate ion) less resulting in in strong bond
- requires more energy to break
What is formed when a Group 2 carbonate is thermally decomposed
- Metal Oxide
- Carbon Dioxide
What is formed when a Group 2 nitrate is thermally decomposed
- Metal Oxide(white solid)
- Nitrogen Dioxide(brown gas)
- Oxygen(colourless gas)
What is formed when a Group 1 carbonate is thermally decomposed
Group 1 compounds are thermally stable
Except Lithium Carbonate which forms a metal oxide and carbonate
What is formed when a Group 1 nitrate is thermally decomposed
Metal Nitrite
Oxygen
except
Describe the trends of melting and boiling points of the halogens
Boiling and Melting points increase down group 7
More electron shells resulting in more electrons
Increase strength of London Dispersion Forces
Describe the trend in electronegativity of the halogens
Decreases down group 7
More electron shells (increase shielding)
Greater distance from nucleus between bonding pair of electron Reducing electrostatic attraction
State the physical states of halogens at R.T
Cl - gas
Br- liquid
I - solid
Describe the trend in reactivity of the halogens
Decreases down group 7
More electron shells greater shielding, greater distance from the nucleus
Weaker electrostatic attraction for an additional electron to bond with
What happens when you react a halogen with a halide ion in an aqueous solution
The more reactive halogen will oxide the halide
For example Chorine oxidises bromide and iodide ions making it the greatest oxidising agent out of the three
Bromine oxidises iodide ions but not chlorine
Iodine cant do any except theoretically astatide
This all means that oxidising ability falls as you go down the Group.
What are the colours are the halogens in an aqueous solution?
Cl2 - Palest Green
Br2 - Yellow
I2 - Brown
What are the colours are the halogens in an organic solution?
Cl2 - Palest Green
Br2 - Red
I2 - Violet
State the reaction between chlorine and water and why is it useful
Disproportionate
Cl2 + H20 –>(reversible) HCl + HOCl(chloric acid)
Use in swimming pools/water treatment
State the reaction between chlorine and cold, dilute alkali and why is it useful
Cl2 + 2NaOH –> NaCl + NaClO+ H20
Sodium chlorate is used for killing bacteria in bleach
State the reaction between chlorine and hot concentrated alkali and why is it useful
Cl2 + 6NaOH –> 5NaCl + NaClO3 + 3H20
Describe the trend of reducing power of the halides by the reaction between sulphuric acid and a halide
Reducing Power Increases as you move down the group
Fluoride ions aren’t a strong enough reducing agent to reduce H2SO4
Chloride ions reduce H2SO4 to HCL(steamy fumes)
Bromide ions reduce to SO2(acidic chocking gas)
Iodide ions reduce to S(yellow solid) or H2S(rotten eggs)
State the colour of the precipitates of the halide with silver nitrate solution
Chloride - White
Bromide - Cream
Iodide - Yellow
State the colour of the precipitates of the halide with silver nitrate solution followed by aqueous ammonia solution
AgCl - precipitate dissolves to give a colourless solution
AgBr - precipitate is almost unchanged using dilute ammonia solution, but dissolves in concentrated ammonia solution to give a colourless solution
AgI - precipitate is insoluble in ammonia solution of any concentration
Why is there no observation between silver nitrate solution and fluoride ions?
Silver Fluoride Dissolves in water
State the reaction between Hydrogen Halide and water
H2O + HCl —> H3O+ + Cl-
State the reaction between Hydrogen Halide and ammonia
NH3(g) + HCl(g) → NH4Cl(s)
How do you test for carbonate ions?
Add an aqueous acid (HCL) to form CO2
Bubble it through limewater which should change from clear to cloudy
How do you test for sulphate ions
First add HCl to remove any impurities
Add barium chloride to form barium sulphate
Barium sulphate is insoluble and will form a precipitate
How do you test for ammonium ions?
Add sodium hydroxide and the ammonium compound together then heat it to produce ammonia gas
Use damp red litmus paper and it should change from red to blue
State the half equation for the test of carbonate ions
2H+ + C03 –> C02 + H20
State the half equation for the test of sulphate
Ba2+ + S04(2-) —> BaS04
State the ionic/half equation for ammonium ions
OH- + NH4+ –> NH3 + H20
