Group 7 - Chlorine, Bromine, Iodine - Revision Flashcards
What is the physical state and colour of Fluorine?
Physical State - Gas
Colour - Yellow
What is the physical state and colour of Chlorine?
Physical State - Gas
Colour - Yellow / Green
What is the physical state and colour of Bromine?
Physical State - Liquid
Colour - Red / Brown
What is the physical state and colour of Iodine?
Physical State - Solid
Colour - Purple
What is the physical state and colour of Astatine?
Physical State - Solid
Colour - Black
What is the test for chlorine gas?
Chlorine bleaches damp litmus paper white
How does the melting and boiling point change as you go further down the group?
It keeps increasing
How does the colour of the element change as you go further down the group?
It keeps getting darker
What is the difference between Hydrogen Chloride (HCl) and Hydrochloric Acid?
Hydrogen Chloride gas is HCl
Hydrochloric Acid is hydrogen chloride dissolved in water
How do you make Hydrochloric Acid with Hydrogen Chloride?
The two ions in hydrogen chloride become detached leaving CL- and H+ ions. H+ is acidic, hence the term acid
Why is hydrogen chloride acidic in water but not in methylbenzene?
Water is a polar molecule
methylbenzene is a non-polar molecule
Hydrogen Chloride is a polar molecule
Polars only dissolve in polars.
When hydrogen chloride is dissolved, you get H+ ions.
These are acidic
Why do Group 7 elements become less reactive as you go down the group?
At the top, the positive charge of the proton in the nucleus is close to the outer shell (as there are only few shells). This makes it easy for them to pull in the one electron they need to become stable, meaning they are very reactive.
At the bottom, there are more shells, which makes the pull of the proton further from the outer shell. This makes it less easy to pull in other electrons. Making it less reactive.
What will a more reactive halogen displace and in what conditions must they be in?
A more reactive halogen will displace a less reactive one that is bonded as a salt.
This will only happen if the salt is dissolved in water or a gas.
What is a redox reaction?
A redox reaction is when a more reactive halogen displaces a less reactive one. This means that one element has been reduced (gained electrons) and one has been oxidised (lost electrons)
(OILRIG) Oxidation Is Loss Reduction Is Gained
What is the reaction of chlorine ions and silver nitrate?
Silver Nitrate + Any Chlorine Ion -> Silver Chloride + Other Part of Ion Nitrate (a white precipitate)
Cl- (aq) + Ag+ (aq) -> AgCl (s)
