<u>Answer:</u> The value of
for the given acid is 
<u>Explanation:</u>
To calculate the molarity of solution, we use the equation:

Initial mass of weak monoprotic acid = 1.00 g
Molar mass of weak monoprotic acid = 180 g/mol
Volume of solution = 300 mL
Putting values in above equation, we get:

To calculate the hydrogen ion concentration for given pH of the solution, we use the equation:
![pH=-\log[H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D)
We are given:
pH = 2.62
Putting values in above equation, we get:
![2.62=-\log[H^+]](https://tex.z-dn.net/?f=2.62%3D-%5Clog%5BH%5E%2B%5D)
![[H^+]=10^{-2.62}=2.40\times 10^{-3}M=0.0024M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-2.62%7D%3D2.40%5Ctimes%2010%5E%7B-3%7DM%3D0.0024M)
The chemical equation for the dissociation of weak monoprotic acid (HA) follows:

<u>Initial:</u> 0.0185
<u>At eqllm:</u> 0.0185-x x x
Evaluating the value of 'x'

So, equilibrium concentration of HA = (0.0185 - 0.0024) = 0.0161 M
Equilibrium concentration of
= x = 0.0024 M
The expression of
for above equation follows:
![K_a=\frac{[H^+][A^-]}{[HA]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
Putting values in above equation, we get:

Hence, the value of
for the given acid is 