pH - Principle and Measurement Review

These flashcards cover the fundamental concepts and details related to pH measurement and its significance in biochemistry, as outlined in the lecture notes.

What is pH defined as in terms of hydrogen ion concentration?

pH is the negative logarithm of the hydrogen ion concentration of an aqueous solution.

According to the pH scale, what value indicates an acidic solution?

A solution with a pH less than 7.

What is the pH range typically found in natural water?

The pH of natural water usually lies in the range of 6.0 to 8.5.

What is the role of a glass electrode in pH measurement?

The glass electrode develops a potential related to hydrogen-ion activity and is the standard method for measuring pH.

How does the pH of stomach acid compare to normal blood pH?

The pH of stomach acid is around 1, while normal blood pH is around 7.4.

What is a buffer in terms of pH control?

A buffer is a substance that stabilizes the hydrogen ion concentration when H+ ions are added or removed from a solution.

Which buffering system is considered the most important in the body?

The bicarbonate buffer system.

What is the typical construction composition of a glass electrode?

72% SiO2, 22% Na2O, and 6% CaO.

What pH range does phenolphthalein change color in?

Phenolphthalein changes from colorless to pink in the pH range of 8.2 to 8.4.

Which ion concentration is measured by pOH?

pOH measures the concentration of hydroxide ions (OH-) in a solution.