Final answer:
To calculate the pH of a 0.200 M HNO2 solution, use the ionization constant (Ka) of HNO2, which is 4.6 x 10-4. The pH of the solution is approximately 2.34.
Step-by-step explanation:
To calculate the pH of a 0.200 M HNO2 solution, we need to use the ionization constant (Ka) of HNO2, which is 4.6 x 10-4. Since HNO2 is a weak acid, it partially ionizes in water to form H3O+ and NO2-. The equilibrium equation for this ionization is: HNO2 (aq) + H2O(l) ⇌ H3O+ (aq) + NO2- (aq)
Using the concentration of HNO2, we can calculate the concentration of H3O+ ions formed. The pH can then be determined using the equation: pH = -log[H3O+].
Let me perform the calculations for you. The pH of a 0.200 M HNO2 solution is approximately 2.34.