3) Group 7 Flashcards
Describe the trend in mpt/ bpt down group 7
- mpt/ bpt increases down group 7
- Number of electrons increases so greater uneven distribution of electrons
- Stronger induce- dipole- dipole attractions
- So more energy required to break the attraction between molecules
- Hence mpt/ bpt increases
Define volatility
This is the ease with which a liquid turns into a gas
Describe the trend in volatility down group 7
- Volatility decreases down the group
- Increase number of electrons
- Increase in the uneven distribution of electrons
- Stronger induce-dipole-dipole attraction
- More energy is needed to overcome the attraction between molecules
Describe the reactivity down the group 7
- Reactivity decreases down a group
- Atoms increases in size down the group/ more shells
- More shielding due to inner shells
- Less nuclear attraction for incoming electrons
- Electron gained less easily
Define oxidising powder
this is the ability of an atom or species to oxidies another species ( take an electron from it)
What is the colour of Cl in water
Pale green
What is the colour of Br in water
Orange
What is the colour of I in water
Brown
What is the colour of I in cyclohexane
Purple/ violet
What is the equation and precipitate formed when Cl is reacted with silver nitrate
Precipitate = white
Equation = Ag+ + Cl- = AgCl
What is the equation and precipitate formed when Br is reacted with silver nitrate
Precipitate = Cream
Equation = Ag+ + Br- = AgBr
What is the equation and precipitate formed when I is reacted with silver nitrate
Precipitate = Yellow
Equation = Ag+ + I- = AgI
What happens to the precipitate when dilute ammonia is added to AgCl
dissolves
What happens to the precipitate when dilute ammonia is added to AgBr
Remains the same
What happens to the precipitate when dilute ammonia is added to AgI
Remains the same