Question

Calculate the pH of a buffer solution when 32.0 mL of a 0.25 M H2CO3 is mixed with 20.0 mL of a 0.15 M NaHCO3​

Answer 1

pH of buffer solution : 4.32

Further explanation

A buffer solution is a solution that can maintain a good pH value due to the addition of a little acid or a little base or dilution.

The buffer solution can be acidic or basic

Acid buffer solutions consist of weak acids(H₂CO₃) and their salts.(NaHCO₃)

mol H₂CO₃

`\tt 0.032* 0.25=0.008`

mol NaHCO₃

`\tt 0.02* 0.15=0.003`

`\tt [H^+]=Ka(mole~weak~acid)/(mole~salt)\\\\(H^+]=1.8* 10^(-5)(0.008)/(0.003)=4.8* 10^(-5)\\\\pH=5-log~4.8=4.32`