Group 7 trends/chlorine Flashcards
what is the trend of electronegativity down the group?
decreases
- more shielding
- distance of shared electrons in H-X bond from nucleus increases
what is the trend of b.p/m.p down the group?
increases
- larger atoms
- more van der waals forces
- more heat energy required to overcome forces
how does boiling point link to volatility?
low b.p = more volatile (ability to evaporate at normal temp)
what is the trend of oxidising ability down the group?
- decreases
what type of reaction occurs when halogen with better oxidising ability reacts with a metal halide?
displacement reaction
what is observed when fluorine reacts with chlorine?
displaces chlorine
what is observed when fluorine reacts with bromine?
orange solution
what is observed when fluorine reacts with iodine?
black solid
what is the trend of reducing ability down the group?
increases
reaction of sodium chloride with concentrated sulfuric acid
- acid-base reaction (NO REDOX)
- steamy fumes of hydrogen chloride
NaCl + H2SO4 → NaHSO4 + HCl
reaction of sodium bromide with concentrated sulfuric acid
- REDOX REACTION: halogen oxidised
- steamy fumes of hydrogen bromide
- colourless SO2
- brown fumes of bromine
NaBr + H2SO4 → NaHSO4 + HBr
2HBr + H2SO4 → SO2 + 2H2O
reaction of sodium iodide with concentrated sulfuric acid
- REDOX REACTION: halogen oxidised
- steamy fumes of hydrogen iodide
- colourless SO2
- bad egg smell of hydrogen iodide
- black solid of iodine
NaI + H2SO4 → NaHSO4 + HI
2HI + H2SO4 → SO2 + 2H2O
6HI + SO2 → 3I2+ 2H2O + H2S
What type of reaction does chlorine undergo when it reacts with water?
disproportionation reaction (it is both reduced and oxidised in same reaction)
what is produced when chlorine reacts with water out of sunlight?
hydrogen chloride and hydrogen chlorate
what is produced when chlorine reacts with water out of sunlight?
hydrogen chloride and oxygen
