Given the list of the following acids:
1. Hydroiodic acid (HI), Ka = 3.2 × 109
2. Ethanoic acid (CH 3COOH), Ka = 1.8 × 10-5
3. Oxalic acid (HO 2C2O2H), Ka = 5.4 × 10-2
4. Boric acid (H 3BO3), Ka = 5.8 × 10-10
5. Carbonic acid (H 2CO3), Ka = 4.4 × 10-7
6. Benzoic acid (C 6H5COOH), Ka = 6.3 × 10-5
a. Calculate the exact pKa values using a calculator.
b. Determine which acid is the strongest.