8.3 Acid Deposition

Natural gas contains on average 5.5 mg / m³ of sulfur in the form of hydrogen sulfide, H₂S (M_r = 34). If a typical household in the UK consumes 0.198 m³ of gas per day, what is the average annual emission of sulfur in g per household?

Nitrous acid is produced when nitrogen dioxide dissolves in water to produce acid rain. What is the correct Lewis structure for nitrous acid?

Hydroxyl free radicals are thought to be involved in complex reactions converting sulfur dioxide into sulfur trioxide in the atmosphere.

OH•  + SO₂ →    •HOSO₂

•HOSO₂ + O₂ → •HO₂ + SO₃  

Which is true?

Iron structures can be damaged by dry deposition such as the equation below:

Fe (s) + SO₂ (g) + O₂ (g)  →   FeSO₄ (s)

Given that,

ΔH_f ^Ө   (SO₂) = -297 kJ mol^-1

ΔH_f^Ө    (FeSO₄)= -929 kJ mol^-1

What is the enthalpy change for this reaction?

Acid deposition results in leaching of aluminium ions from the soil. Which are true?

1. Al³⁺ ions damage plants roots
2. Al³⁺ ions damage fish gills
3. Al³⁺ ions affect human health

The equilibrium constants for the dissociation of nitrous and sulphurous acid found in acid rain are as follows:

HNO₂ (aq) ⇌  H⁺ (aq) + NO₂^- (aq)     K_c¹ =  7.2  10^-4 mol dm^-3

H₂SO₃ (aq) ⇌  H⁺ (aq) + HSO₃^- (aq)    K_c² = 1.3  10^-2 mol dm^-3

Which is true?

How many different types of ions can be found in acid rain, assuming it contains a mixture of sulfuric, sulfurous, nitric and nitrous acids?

Historic buildings and statues have frequently suffered chemical corrosion from acid rain. Which building materials would be unaffected by this?

Which is true about the hydrogensulfate ion, HSO₄^-, found in acid rain?

1. It is amphiprotic
2. It is amphoteric
3. Sulfur is in its highest oxidation state