pH question?

Question

What is the most accurate way an unknown pH can be determined?

How can an indicator be used to measure the pH of a solution?

Answer 1

The most "accurate" way pH can be measured is with an instrument called a potentiometer (or a pH meter- pH stands for potential of Hydrogen). Basically, there is a hydrogen reference electrode inside a semi-permeable membrane. The instrument measures the difference in H+ ion concentration between the reference electrode and the solution, and from there quite accurately determines the pH.

An indicator uses a principle informally called visual colorimetry. Varying dyes are impregnated on a strip that change color as they are put in various pH's. A chart is by the pH strips that can be used to easily differentiate the pH. Moderately accurate method - depending on the indicator strip used.

hope this helps.

Answer 2

From a practical point of view, pH meters measure quite accurately. Indicators are compounds which are usually dyes. In a certain pH range, the compound undergoes an acid-base reaction in water which changes the color of the dye. Different compounds work at different pH levels.

Answer 3

pH indicators are usually just strips of treated paper that you place a few drops of your solution on. the color of the paper after being exposed to the solution will give you an approximate pH. the most accurate way however is to use a pH probe.

Answer 4

depends on the solution but a simple ph test kit is easy to get and use