0.10 moles HCOOH (formic acid) and 0.02 moles HCOONa (sodium formate) are dissolved in a liter of water. what is the resulting pH solution?

To determine the resulting pH of the solution, we need to calculate the concentration of hydronium ions (H3O+) in the solution. This will depend on the dissociation of the formic acid (HCOOH) and the sodium formate (HCOONa) in water.

1. Dissociation of formic acid (HCOOH):
HCOOH β‡Œ H+ + HCOO-

Formic acid is a weak acid, meaning it only partially dissociates in water. We can assume that the concentration of HCOOH that dissociates is negligible compared to the initial concentration of the formic acid (0.10 moles).

2. Dissociation of sodium formate (HCOONa):
HCOONa β‡Œ Na+ + HCOO-

Sodium formate is the salt of formic acid, and it can act as a weak base in water by accepting protons (H+) from water. The hydrolysis of sodium formate leads to the formation of an equal concentration of hydroxide ions (OH-) and a small concentration of hydronium ions (H3O+).

Now, we can calculate the concentration of hydronium ions in the solution using the equilibrium between HCOO- and H3O+:

[HCOO-] = [H3O+]

The concentration of sodium formate (HCOONa) is 0.02 moles. Since HCOONa dissociates completely into HCOO- ions, the concentration of HCOO- is also 0.02 moles.

Therefore, the concentration of hydronium ions ([H3O+]) is also 0.02 moles.

Finally, we can calculate the pH of the solution using the formula:

pH = -log[H3O+]

pH = -log(0.02)

Using a calculator, the resulting pH of the solution is approximately 1.70.