To calculate the hydronium ion concentration in a solution, we need to understand the chemical properties of the compound involved. In this case, we have a solution of sodium formate, NaHCO2.
When sodium formate dissolves in water, it ionizes into its constituent ions: sodium ions (Na+) and formate ions (HCO2-). However, formate ions also act as weak acids and can donate a proton (H+) to water, creating hydronium ions (H3O+). This is the equilibrium reaction:
HCO2- + H2O ⇌ H3O+ + HCO3-
Since NaHCO2 is a strong electrolyte, we can assume that all of it dissociates completely. Therefore, the initial concentration of formate ions is the same as the concentration of NaHCO2, which is 0.037 M.
Now, we need to consider the equilibrium reaction mentioned above. At equilibrium, there will be some concentration of hydronium ions formed. However, we can assume that the concentration of formate ions left (HCO2-) is negligible compared to the initial concentration, since it is a weak acid. As a result, we can consider the hydronium ion concentration to be equal to the formate ion concentration.
Therefore, in this case, the hydronium ion concentration in the 0.037 M solution of sodium formate is approximately 0.037 M.
Now, let's move on to calculating the pH.
pH is a measure of the acidity or basicity of a solution and is defined as the negative logarithm (base 10) of the hydronium ion concentration.
pH = -log[H3O+]
In our case, the hydronium ion concentration is 0.037 M. Therefore, we can calculate the pH as follows:
pH = -log(0.037)
Using a calculator, the pH of the 0.037 M solution of sodium formate is approximately 1.43.