Unit 2: Section 3 - Reactions and Elements - Halide Ions

Question 0

Reaction of NaCl and sulfuric acid

Is this a redox reaction?

Answer 0

NaCl(s) + H2.SO4(aq) —> NaHSO4(s) + HCl(g)

No, states of Halide and S remain -1 and +6

Question 1

Reaction of NaF with sulfuric acid

Is this a redox reaction?

Answer 1

NaF(s) + H2.SO4(aq) —> NaHSO4(s) + HF(g)

No, states of Halide and S remain -1 and +6

Question 2

Reaction NaBr and sulfuric acid to (eventually) produce a gas

Is this a redox reaction?

Answer 2

1) NaBr(s) + H2.SO4(aq) —> NaHSO4(s) + HBr(g)
2) 2HBr(g) + H2.SO4(aq) —> SO2(g) + Br2(g) + 2H2.O(l)

Yes, halide goes from -1 to 0 and S goes from +6 to +4

Question 3

Reaction of NaI and sulfuric acid to produce a toxic gas

Is this a redox reaction?

Answer 3

NaI(s) + H2.SO4(aq) —> NaHSO4(s) + HI(g)

2HI(g) + H2.SO4(aq) —> SO2(g) + I2(s) + 2H2.O(l)

6HI(g) + SO2(g) —> H2.S(g) + 3I2(s) + 2H2.O(l)

Yes, halide goes from 0 to -1 and S goes from +6 to -2

Question 4

Observation for HF, HCl, HBr and HI being produced

Answer 4

Misty fumes, it’s acidic so will turn litmus paper red

Question 5

Observation for SO2 being produced

Answer 5

Choking fumes (with bromide so orange fumes of Br2 also if so

Question 6

Observation for H2S

Answer 6

Toxic gas which smells of bad eggs