Question

The pH value of gasfric juice in humna stomach is about 1.8 and in intiestine , it is about 7.8. The `pk_(a)` value of aspirin is 3.5 Aspirin will be
A. completely ionised in the small intestine and in the stomach
B. unionised in the small intestine and in the stomach
C. unionised in the small intestine and almost unionised In the stomach
D. ionised the stomach and almost unionised in the small intestine

Answer 1

Correct Answer - C
Aspirin, is a moderate acid `(pK_1= 3.5)`, hence is almost unionised in stomach due to strong acidic medium of it (because of HCI), this is due to common ion effect. While in small intestine, the medium is alkaline, hence, aspirin will be sufficiently ionised in small intestine.