Dear beloved readers, welcome to our website! We hope your visit here brings you valuable insights and meaningful inspiration. Thank you for taking the time to stop by and explore the content we've prepared for you.
------------------------------------------------ Calculate the pH of the following aqueous solution: 0.5 M H₂CO₃ (pKa₁ = 6.37; pKa₂ = 10.25). What is the pH range?

a) pH < 4.00
b) 4.00 < pH < 6.00
c) 6.00 < pH < 8.00
d) pH > 8.00

The pH of the solution can be calculated using the pKa values of the weak acid, H2CO3. Since H2CO3 is a diprotic acid, it can donate two protons (H+) in water.

The pH of the solution is determined by the concentration of H+, which is related to the dissociation of H2CO3.

To calculate the pH, we first need to determine which of the two acid dissociation reactions is dominant.

Using the information provided, we find that the concentration of H2CO3 is 0.5 M, which is greater than the concentration of HCO3-, indicating that the reaction H2CO3 ⇌ H+ + HCO3- is dominant.

Next, we can use the Henderson-Hasselbalch equation to calculate the pH:

pH = pKa + log([A-]/[HA])

Applying this equation, we get:

pH = 6.37 + log([HCO3-]/[H2CO3])

Since the concentration of HCO3- is equal to the concentration of H2CO3 (0.5 M), the ratio of [HCO3-]/[H2CO3] is 1. Therefore, the equation simplifies to:

pH = 6.37 + log(1) = 6.37

Therefore, the pH of the 0.5 M H2CO3 solution is approximately 6.37.