Question

The pH of Human small intestine is around 7.5 and the ph of large intestine can be 5.5. As substances travel from the small intestine to large intestine, what would happen to the $H^{+}$ ions concentration?

• A. Increases 20 Fold
• B. Increases 2 Fold
• C. Increases 10 Fold
• D. Increases 100 Fold

Answer 1

The correct option is D Increases 100 Fold

We, know

$pH=$ $-log\left[H^{+}\right]$

The difference in pH of the small intestine and the large intestine is\

$-log\left[H_{smallintestine}^{+}\right]-(-log[H_{largeintestine}^{+}\left]\right)$ = 7.5 - 5.5

$log\left[H_{largeintestine}^{+}\right]-log\left[H_{smallintestine}^{+}\right]$ = 2

$log\left[H_{largeintestine}^{+}/H_{smallintestine}^{+}\right]$ = 2

taking antilog

$H_{largeintestine}^{+}/H_{smallintestine}^{+}$ = ${10}^2$

$H_{largeintestine}^{+}/H_{smallintestine}^{+}$ = 100

So, the $H^{+}$ ion concentration will increase 100 fold.