U2S2 halide ions

Question 1

What s a halide ion

Answer 1

Group 7 element gains an electron to form a 1- ion

Question 2

What happens when a halide ion takes place in a redox reaction

Answer 2

Reduces something and is oxidised itself

Question 3

What is the trend in reducing power of halides as go down group

Answer 3

• increases
• more distance and shielding means weaker attraction

Question 4

What is the role of the halide ions and sulfuric acid when the two react

Answer 4

• halide ions are reducing agents
• sulfuric acid is oxidising agent

Question 5

What is the reaction for NaCL/NaF with sulfuric acid

Answer 5

H2SO4(l) + NaCl(s) -> NaHSO4(s) + HCl(g)
- misty fumes

Question 6

What is the reaction of NaBr with sulfuric acid

Answer 6

2H2SO4(l) + 2NaBr(s) -> Na2SO4(s) + Br2(g) + SO2(g) + 2H2O(l)
- choking fumes of SO2 and orange fumes of Br2

Question 7

What is the reaction of NaI with sulfuric acid

Answer 7

NaI(s) + H2SO4(l) -> NaHSO4(s) + HI (g)
2HI(g) + H2SO4(l) -> I2 + SO2(g) +2H2O(l)
6HI(g) + SO2 -> H2S(g) + 3I2(s) + 2H2O(l)
- fumes of H2S and solid iodine