C All topic Flashcards
What is the trend in ionisation energy down the group?
Decreases
Although the nuclear charge increases, the electrons have an extra shell of sheilding which make them easier to remove as the outer electron is futher away form the nucleus.
Metal + water produces what
metal hydroxide + h2
What is the trend in solubility of hydroxides down group 2?
Increases
What are the group 2 oxide reactions?
A group 2 oxide reaccts with water to form an alkali
What is the milk of magnesium used for?
Used as antacids to neutralise the HCL in the stomach
What is the trend of sulphates down group 2?
decreases
Test for sulphate ions?
Add barium sulphate and a dilute caid.
Trend for thermal stability in group 1 and 2 nirates and carbonates
G2 are less thermally stable than G1 us further up the group they have large electron densities since the ionic redius is smaller. This makes the ion more polarising so it distirts the ion more making it less thermally stable.
decomposition of nirtates
metal ocide, NO2 +O2
Test for ammoniums
Add sodium chloride and warm the mixture
Red to blue litmus colour change
Adding HCL produces white ammonium chloride fumes
trend in electronegativity down the halogens?
decreases
more sheilding
Halide displacment reactions
In water
bromine - yellow/ organge
chlorine - very pale green
iodine - brown
In organic
= iodine - violet / purple gas
What is the reaction between chlorine and sodium hydroxide?
Disproportionation
cold aqueous sodium hydroxide:
Cl2 + 2NaOH produces NaCl + NaClO + H2O
hot concentrated sodium hydroxide
3Cl2 +6NaOH produces 5NaCl + NaClO3 + 3H20.
trend in oxidising and reducing agents
higher up the group, stronger the oxidising agent, weaker the reducing agent.
Reactions of halide ions and sulphuric acid
chlorine is the worst reducing agent
NaCl + H2SO4 produces NaHSO4 + HCl
bromine reduces to form SO2 and iodine further reduces to form S, SO2, H2S
