3.2.3 Group 7 halogens Flashcards
(20 cards)
What are the trends in electronegativity in group 7 and why?
Electronegativity decreases because atomic radius increases and therefore so does shielding so the atom’s ability to attract electrons decreases
What is the trend in boiling point in group 7 and why?
Boiling point increases as you go down the group because the atomic radius will increases and therefore more van der waal forces present which require more energy to break
What is the trend in oxidising ability as you go down group 7 and why?
The oxidising ability decreases because the atomic radius increases and therefore more shielding which causes the atom to have a weaker attraction to electrons
What is evidence for the trend in oxidising ability as you go down group 7?
The fact that the top element in the group displace the bottom ones:
Chlorine can displace bromide and iodide.
Bromine can only displace iodide.
Iodine can’t displace any halides.
What is the trend in reducing ability as you go down group 7 and why?
Reducing ability increases because atomic radius increases and therefore so does shielding which makes it easier to lose an electron
Why don’t Chlorine and Fluorine react with Concentrated Sulfuric Acid?
Their reducing strength is too weak
How is acidified silver nitrate solution used to distinguish between halide ions?
By firstly adding dilute nitric acid (HNO3) to the solution to remove any carbonate or hydroxide ions that will interfere by forming their own precipitates
Add silver nitrate (AgNO3) and precipitate of silver halide should form
What is trend in solubility of silver halides in ammonia?
It will increase because as you go down the group the bond strength between the silver and halide is weaker
AgCl = Weakest Bond
AgI = Strongest Bond
Why is silver halide used to identify halide ions?
Because it reacts with halide ions to form insoluble precipitates
the colours of the precipitate are easily distinguishable
Additional test can be ran with ammonia which can help separate the halides based on solubility
Products of Chlorine’s reaction with water?
ClO- (chlorate ions)
Cl- (chloride ions)
What type of reaction is water + Chlorine
Disproportionation
What is disprortionation?
When an elements undergoes oxidation and reduction in the same reaction
What are the 2 uses of adding chlorine to water?
- Chlorine in water kills bacteria in drinking water and swimming pools
- HClO- is an ingredient of household bleach
Products of Chlorine’s reaction with water in sunlight?
Hydrochloric acid (HCL) and Oxygen (O2)
Advantages of adding chemicals to water supplies
Disadvantages of adding chemicals to water supplies
How do the benefits to health of the watter treatment outweighs its toxic effects?
What is the reaction of Na with water?
What is the reaction of Na
im missing 3.2.4
