A 20.0 mL of 0.27 M solution of the salt NaA has a pH of 8.70. a) Calculate the pk, value of the acid HA.

(Correct to 3 sig. fig)

b) Calculate the pH of a solution containing 0.3 M HA and 0.1 M NaA.

(Correct to 3 sig. fig)

Thanks!!

a) 3.969

b) 3.487

Explanation:

Given data:

m =  0.27 M

pH = 8.7

a) Calculate PKa of acid HA

pH value = 1/2 ( Pkw + Pka + log C )

    8.7 * 2 = 14 + log C + Pka

        17.4 = 14 + log ( 0.27 ) + Pka

∴Pka = 17.4 - 14.5686 = 3.9686 ≈ 3.969

b) Calculate the pH of solution

pH = pKa + log ( salt / acid )

     = 3.9686 + log ( 0.1 / 0.3 )

     = 3.487

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.