Reactivity Trends Flashcards
What is a group 2 element in a redox reaction?
The reducing agent
Why does the ionisation energy decrease down group 2?
The attraction between the nucleus and the outer electrons decreases as a result of increasing atomic radius and increasing shielding
What happens to the solubility of hydroxides as you travel down group 2?
Increases
Also the pH and alkalinity of the hydroxides increases as well
How are group 2 hydroxides used in agriculture?
Added as like to acidic soils to increase pH
Why do group based relieve indigestion?
Neutralise stomach acid
Which group is the halogens?
7
What kind of molecules are the halogens?
Diatomic
What happens as you travel down group 7?
More electrons
Stronger ldf
More energy needed to break ldf
Boiling point increases
What are the most common reactions of group 7?
Redox reactions
What happens to group 7 in a redox reaction?
Reduced
What is a group 7 element in a redox reaction?
Oxidising agent
What happens to the reactivity of the halogens as you travel down the group?
Decreases
How can you show the decrease in reactivity of the halogens?
A displacement
- halogens will be unable to displace halide from water
What happens to halogens structure as you travel down the group?
Atomic radius increases
More inner shells - more shielding
Less nuclear attraction
Less reactivity
What is disproportionation?
A redox reaction where the same element is both oxidised and reduced
Give an example of a disproportionation reaction
Chlorine with water
Cl2 + h2o -> HClO + HCl
0. ->. -1
0. ->. +1
What is a test for a halide ion?
Precipitation reaction with aqueous silver ions
What does qualitative analysis rely on?
Simple observations
What is the carbonate rest?
Add dilute nitric acid
If it bubbles should be carbonate
To prove bubble through lime water will go milky
What is the sulfate test?
Barium added if it’s a sulphate will make a precipitate
What are the different colours in a halide test?
White - chloride
Cream - bromide
Yellow - iodide
What do you do after the halide test to check?
Add ammonia to test solubility of halides
Dilute - chloride
Conc - bromide
Insoluble - iodide
What is a barium meal?
A patient swallows water with barium sulphate in it which costs the inner lining of the gut allowing doctors to check for abnormalities
What is the correc order for all the anion tests?
Carbonate
Sulfate
Halide
