Group 7 Halogens Flashcards
What are the colors and physical states of Halogens at room temperature?
Chlorine: Green and is a gas.
Bromine: Brown and is a liquid
Iodine: Dark grey and is a solid
What are the melting and boiling points of these elements?
The melting and boiling points increase as you go down the group. As the relative molecular mass increases, the intermolecular forces of attraction become stronger. Therefore more energy must be put in to overcome these stronger forces of attraction.
Knowledge of trends to predict physical properties of Group 7.
The further you go down the group the less reactive it becomes. This makes Fluorine the most reactive element in group 7 and Astatine one of the most unreactive.
What are the displacement reactions involving Halogens and Halides to prove the trend of reactivity?
We can use displacement reactions to show that chlorine is more reactive than Bromine, which is then more reactive than iodine. An element can only displace another if they are more reactive than the element it is trying to displace.
2KBr + Cl2 -> 2KCl + Br2
Chlorine is more reactive than Bromine and has displaced the Bromine from the solution. The chlorine solution to colorless potassium bromide, then when bromine is formed the solution turns orange.
Explain the trend of reactivity of the halogens?
When Halogens react they form 1- ions taking the electrons away from something else. If a shell is closer to the nucleus the faster it attracts the electron to itself.
