Question

Explain how is a pH meter measures the hydrogen ion concentration in an aqueous solution by describing the principle involved including the overall electrode set up, function of the ion selective membrane

Answer 1

The main points: 1. inside glass Bulb equal H⁺ and OH^-. But membrane permeable only for H⁺ so in acidic environment H+ pass in probe number of H⁺ increases.

In alkaline condition H+ coming out to react excess OH^- thus now number of OH^- increases in glass Bulb accordingly difference in potential and likewise PH displayed.

2.function of ion selective membrane to allow only H⁺.

This setup has thin glass membrane permeable by H⁺ ions

Electrode filled with neutral solution is equal number of H⁺ ions and OH^- ions.