topic 4- inorganic Chemistry Flashcards
How do you test for Halide ions in solution? and give observations
Add silver nitrate (aq) and nitric acid.
Cl- = white
Br- = cream
I- = pale yellow
What is the test for sulfate ions? Include observations
Barium Chloride and a white precipiate should form that is insoluble in HCl
What is the trend in thermal stability of group 2 carbonates?
Carbonates become more thermally stable down the group as there is less polarising effect so the carbonate bond becomes less weak.
What is the trend in solubility of group 1/2 hydroxides?
More soluble down the group
Explain the trend in thermal decomposition of nitrates
Become more thermally stable down group
Charge density decreases as atom size increases
Less polarising effect so bond becomes less weak
What are the observations of halide ions when H2SO4 is added?
- H₂SO₄
- F/Cl - white steamy fumes
- Br- red fumes of Br₂
- I- purple fumes
What is observed when nitrates undergo thermal decomposition?
Brown gas of NO2 evolves
Explain the trend of melting points in group 7
- melting point increases down the group
- as the number of electrons increases the strength of london forces increases
- so more energy required the overcome these forces.
Explain the trend on electronegativity of group 7
- Decreases down the group
- As number of shells increases, the nucleus is less able to attract bonding pairs.
What is the trend in solubility of group 2 nitrates?
Become less soluble down the group.
Explain the trend in electron affinities in group 7
- Electron affinities become less negative down the group (more endo)
- added electron is further from nucleus and there is more shielding from full shells
