topic 4 Flashcards
in the other chemistry folder
do atom sizes increase or decrease down the periodic table?
increase
do atom sizes increase or decrease across the periodic table?
decrease
what are 3 factors that impact ionisation energies?
- nuclear radius (smaller=stronger)
- nuclear attraction
- # of shielding(Same as electro negativity)
does reactivity increase or decrease down group 2?
increase
does boiling point increase or decrease down group 2?
decrease
does boiling point increase or decrease down group 7?
increase
does reactivity increase or decrease down group 7?
decrease
G2 Metal + O2 ->
2MO (s)
G2 metal oxide + H2O ->
M(OH)2 (aq)
G2 Metal + Cl2 ->
MCl2 (s)
G2 Metal + 2H2O (l) ->
M(OH)2 + H2
Does solubility of G2 metal hydroxides increase or decrease down the group? Why?
increase,
because ionic radius increases so it is easier to break
1- ions
HydroxIIIIdes
Mg + H2O(g/steam) ->
MgO (s) + H2 (g)
Does G2 metal sulphate solubility increase or decrease down the group?
decrease down
Bcs 2- ions
SSSSulphate - leSSSS
Ba(NO3)2 (aq) + Na2SO4 (aq) ->
Barium nitrate + Sodium sulfate ->
BaSO4 (s) + 2 NaNO3 (aq)
Barium sulfate + Sodium nitrate
Ca(OH)2 (aq) + CO2 (g) ->
CaCO3 (s) + H2O (l)
what are G2 metal oxides and hydroxides used for?
Neutralisation reactions and agriculture
what is formed when brown fumes are observed?
NO2
Nitrogen dioxide
what is the definition of thermal stability?
How much a compound decomposes under heat
What are 3 factors that affect thermal stability?
- ionic radius
- outermost shell e- quantum shell
- charge density/of cation - 2+ stronger than 1+)
Is a smaller ion more or less thermally stable? And why?
smaller = higher charge density/more polarising = less thermal stability
How do you know if a compound is more thermally stable than the other?
less decomposition = more thermally stable
what is the procedure for flame tests?
- Nichrome wire
- dip in conc. HCl
- heat under blue bunsen flame
what are 2 issues with flame tests?
- colours are subjective
- impurities can affect colour
does reactivity increase or decrease down group 7? Why?
decrease
bcs they have more London Forces from increased e-s and protons
so more energy is needed to break stronger LFs
What affects the electronegativity?
- atomic radius
- number of shells
as electronegativity decreases, stability…..
increases
2HI + NaSO4 ->
NaHSO4 + HI (misty fumes)
Acid base reaction
6 HI + H2SO4 ->
3 I2 + S + 4H2O
S is a yellow solid
Redox reaction
8HI + H2SO4 ->
H2S + 4 I2 + 4H2O
H2S has egg smell
CaCO3 (or decomposition of any G2 carbonates) ->
CaO + CO2
What is the physical state of G1/G2 nitrates and carbonates?
White solid
When brown fumes are observed after heating, what can i assume it is?
Nitrogen dioxide NO2
G1 nitrates decomposition
2NaNO3(s) ->
2NaNO2(s) + O2 (g)
G2 nitrate decomposition:
Be(NO3)2 (s) ->
BeO (s) + 2NO2 (g) + 1/2 O2 (g)
What is the trend of G7 elements down?
Decreasing reactivity down
As Electronegativity decrease
Bp mp increase
2Li (s) + Cl2 (g) ->
2LiCl (s)
Ba (s) + Br2 (l) ->
BaBr2 (s) (white solid)
Why are G7 ions more likely to displace those lower down the group?
Because they’re smaller, so incoming electron is more attracted by their protons
Smaller number of complete inner energy levels of e-, so less repulsion
Cl2 (g) + H2O (l) ->
HCl (aq) + HOCl (aq)
Example of disproportionation
Why is chlorine used in water?
Disinfect for drinking purposes
By killing pathogens and water bourne diseases
What is the reducing power trend down G7?
Increasing down
As more stabilising bcs it’s less polarising
What is formed and their observations when sulfuric acid + sodium chloride?
Misty fumes
HCl formed
What is formed and their observations when sulfuric acid + sodium bromide? (In a redox reaction)
Misty fumes (HBr) brown fumes (Br2)
Colourless with choking smell (SO2)
NaBr + H2SO4 → NaHSO4 + HBr
2HBr + H2SO4 → Br2 + SO2 + 2H2O
What is formed and their observations when sulfuric acid + sodium iodide?
Misty fumes (HI)
Purple fumes/ black solid (iodine)
Sulfur dioxide (colourless, choking smell)
Sulfur (yellow solid)
Hydrofrm sulfide (H2S) (colourless gas with rotten egg smell)
2 LiNO3 (decomposition)->
Li2O + NO2 + 3/2 O2
NaNO3 ->
NaNO2 + 1/2 O2
Same for all other G1 metals except Li
What does polarising mean?
ability of cation to pull the electron density of anion towards itself
What’s the equation for chlorine reacting with cold dilute sodium hydroxide? And name the type of reaction. (2 marks)
Cl2 + 2OH- -> H2O + Cl- + ClO-
Disproportionation
What’s the equation for chlorine reacting with cold dilute sodium hydroxide? And name the type of reaction. (2 marks)
Cl2 + 2OH- -> H2O + Cl- + ClO-
Disproportionation
Are G1 or G2 hydroxides more soluble?
G1 are more soluble
Which G2 metal does not react with water?
Beryllium
What does S (s) look like?
yellow solid
What ions are always soluble?
NAG SAG
Nitrates
Acetates
Group 1
Sulfates
Ammonium
Group 7
What are the exceptions to the solubility rules?
PMS Castro Bear
Pb (lead)
Mercury
Silver
Caesium
Strontium
Barium
