Answer:
4.0 × 10⁻⁶
Weak acid
Explanation:
Step 1: Calculate [H⁺]
We know that the pH is 2.50. We will calculate [H⁺] using the following expression.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -2.50 = 3.16 × 10⁻³ M
Step 2: Calculate the acid dissociation constant (Ka)
We will use the following expression.
[tex]Ka = \frac{[H^{+}]^{2} }{Ca}[/tex]
where,
Ca is the concentration of the acid (2.5 M)
[tex]Ka = \frac{[H^{+}]^{2} }{Ca} = \frac{(3.16 \times 10^{-3} )^{2} }{2.5}= 4.0 \times 10^{-6}[/tex]
Since Ka << 1, the acid is weak.
