Question

Calculate the

Answer 1

Answer:

$\large \boxed{4.7}$

Explanation:

HA + H₂O ⇌ H₃O⁺ + A⁻

(a) Calculate pKₐ

$\text{p}K_{\text{a}} = -\log \left (K_{\text{a}} \right ) =-\log(1.8 \times 10^{-5}) = 4.74$

(b) Calculate the pH

We can use the Henderson-Hasselbalch equation to get the pH.

$\begin{array}{rcl}\text{pH} & = & \text{pK}_{\text{a}} + \log \left(\dfrac{[\text{A}^{-}]}{\text{[HA]}}\right )\\\\& = &4.74 +\log \left(\dfrac{0.01}{0.01}\right )\\\\& = & 4.74 + \log1.0 \\& = & 4.74 +0.0\\& = &4.7 \\\end{array}\\\text{The pH is \large \boxed{\textbf{4.7}} }$