Group 7 Halogens Flashcards
(28 cards)
What happens to the atomic radius as you go down the group in group 7
Increases, due to additional shells
What happens to the reactivity as you go down the group in group 7
Decreases, atomic radius increases, increases shielding
What happens to the ionisation energy as you go down the group in group 7
Decreases, due to atomic radius and shielding
What happens to the boiling point as you go down the group in group 7
Increases, van der waal’s forces increases down the group requiring more energy to overcome them
What happens to the oxidising power as you go down the group in group 7
Decreases, due to increasing shielding and greater atomic radius
What happens to the reducing power as you go down the group in group 7
Increases, due to increasing shielding and atomic radius
Reaction with H2SO4 with Cl ions ( must be known for Cl and F)
NaCl + H2SO4 —> NaHSO4 + HCl
Reaction with H2SO4 with Br ions
NaBr + H2SO4 —> NaHSO4 + HBr
2HBr + H2SO4 —> Br2 + SO2 + 2H2O
Reaction with H2SO4 with Iodide ions
NaI + H2SO4 —> NaHSO4 + HI
2HI + H2SO4 —> I2 + SO2 + H2O
6HI + SO2 —> H2S + 3I2 + 2H2O
Cl- ions with AgNO3
white precipitate (AgCl)
Br- ions with AgNO3
cream precipitate (AgBr)
I- with AgNO3
yellow precipitate(AgI)
Cl- ions with dilute NH3
precipitate dissolves
Br- ions with dilute NH3
no change
I- ions with dilute NH3
no change
Cl- ions with conc. NH3
precipitate dissolves
Br- ions with conc. NH3
precipitate dissolves
I- ions with conc. NH3
no change
Chlorine reacts with cold water
Cl2 + H2O —> HClO + HCl
Chlorine with water in UV light
2Cl2 + 2H2O —> 4HCl + O2
Bleach Production
2NaOH + Cl2 —> NaClO + NaCl + H2O
How are sulfates (SO4^2-) tested
Use BaCl2, forms a white precipitate
How are hydroxides (OH-) tested
Use red litmus, that turns blue
or
Universal indicator that turns blue-purple
How are carbonates (CO3^2-) tested
Add acids, effervescence and CO2 gas is given off
Limewater turns cloudy, confirming CO2
