Question

Calculate the ph of a buffer that is 0.145 m hc2h3o2 and 0.202 m kc2h3o2. The ka for hc2h3o2 is 1.8 × 10-5.

Answer 1

pH = 4.8

Step-by-step explanation:

A buffer is formed by a weak acid (0.145 M HC₂H₃O₂) and its conjugate base (0.202 M C₂H₃O₂⁻ coming from 0.202 M KC₂H₃O₂). The pH of a buffer system can be calculated using Henderson-Hasselbalch's equation.

`pH = pKa + log([base])/([acid]) \\pH = -log(1.8 * 10^(-5) )+log((0.202M)/(0.145M) )\\pH=4.8`