Group 7 Flashcards
Observation of Cl2 + Br-
Yellow solution (Br2) forms
Equation Cl2 + Br-
Cl2 + 2Br- —> 2Cl- + Br2
Observation Cl2 + I-
Brown solution forms (I2 forms)
Equation Cl2 + I-
Cl2 + 2I- —> 2Cl- +I2
Observation Br2 + Cl-
Stays yellow solution (no reaction)
Observation Br2 + I-
Brown solution forms (I2 forms)
Equation Br2 + I-
Br2 + 2I- —> 2Br- +I2
Observation I2 + Cl-
Stays brown solution (no reaction)
Observation I2 + Br-
Stays brown solution (no reaction)
What state are all reactants in?
Aq
Reaction of chlorine and water
Cl2 (aq) + H2O(l) <—> HCl (aq) + HClO(aq)
What type of reaction is chlorine + water?
Disproportionation- chlorine gets both oxidised and reduced
How to make bleach?
Chlorine gas mixed with cold, dilute, aqueous sodium hydroxide
Equation to make bleach?
2NaOH (aq) + Cl2 (g) <—> NaClO (aq) + NaCl (aq) + H2O (l)
Cl- reaction with H2SO4- product & observation
HCl- steamy (white fumes)
Cl- equation of reaction and type of reaction
NaCl + H2SO4 —> NaHSO4 + HCl. (Acid-base)
Br- products & observations
HBr- steamy fumes
Br2- brown fumes
SO2- colourless (choking) gas
Products of I- reaction
HI- steamy fumes
I2- purple fumes
SO2- colourless gas
S- yellow solid
H2S- gas (bad egg smell)
What happens when water + chlorine in sunlight
Chlorine decomposes water to form chloride and oxygen
Reaction of chlorine + water in sunlight
2Cl2 (g) + 2H2O (l) <—> 4H+ (aq) + 4Cl- (aq) + O2 (g)
Half equation of H2SO4 to form SO2
H2SO4 + 2H+ + 2e- —> SO2 + 2H2O
Half equation for H2SO4 to form S
H2SO4 + 6H+ + 6e- —> S + 4H2O
Half equation for formation of H2S from H2SO4
H2SO4 + 8H+ +8e- —> H2S + 4H2O
