Problem: In the atmosphere, sulfur dioxide and nitrogen dioxide react with water to give sulfurous acid and nitric acid. This produces “acid rain” which has a pH below 7 and can dissolve limestone. Sulfur dioxide, SO2, acts as a diprotic acid in aqueous solution. At 25°C the acidity constants are:SO2 (aq) + 2H 2O (l) ⇋ HSO3– (aq) + H3O+ (aq)               K a1 = 1.54 x 10–2HSO3– (aq) + H2O (l) ⇋ SO32– (aq) + H3O+ (aq)              K a2 = 1.02 x 10–7The concentration of sulfur dioxide in water saturated with sulfur dioxide is 1.5 M. What is the concentration of hydrogen sulfite (HSO3–) in solution?A. 0.152 MB. 0.441 MC. 0.160 MD. 1.356 ME. 0.144 M

FREE Expert Solution

We are being asked to calculate the concentration of hydrogen sulfite (HSO3) in the solution if the concentration of sulfur dioxide in water saturated with sulfur dioxide is 1.5 M


We're going to calculate the concentration of hydrogen sulfite using the following steps: 

Step 1: Construct an ICE chart for the equilibrium reaction.
Step 2: Write the Ka is an equilibrium expression.
Step 3: Calculate for the equilibrium concentration.


Step 1: Construct an ICE chart for the equilibrium reaction.

Since we’re dealing with a weak acid and Ka is an equilibrium expression, we will have to create an ICE chart to determine the equilibrium concentration of each species:

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Problem Details

In the atmosphere, sulfur dioxide and nitrogen dioxide react with water to give sulfurous acid and nitric acid. This produces “acid rain” which has a pH below 7 and can dissolve limestone. 

Sulfur dioxide, SO2, acts as a diprotic acid in aqueous solution. At 25°C the acidity constants are:

SO2 (aq) + 2H 2O (l) ⇋ HSO3 (aq) + H3O(aq)               K a1 = 1.54 x 10–2
HSO3– (aq) + H2O (l) ⇋ SO32– (aq) + H3O(aq)              K a2 = 1.02 x 10–7

The concentration of sulfur dioxide in water saturated with sulfur dioxide is 1.5 M. What is the concentration of hydrogen sulfite (HSO3) in solution?

A. 0.152 M

B. 0.441 M

C. 0.160 M

D. 1.356 M

E. 0.144 M