If the pH of a solution of HCl is 4, what is its H3O+ concentration (in mol/L)?

1. 0.6128
2. 6.1 × 10-1
3. 4.0 × 10-5
4. 1.0 × 10-4

When added to an aqueous solution, fatty acids arrange themselves in the form of:

1. Micelles
2. Detergents
3. Glycolipids

Which statement is not correct about acid-base chemistry?

1. The larger the Ka, the stronger the acid
2. A small pKa correspond to a small Ka
3. The smaller the pKa, the stronger the acid