p = -log
H= concentration of hydrogen in solution (H+)
therefore,
pH= -log [H+]
or
[H+] = 10-pH
Each indicator has a specific change of color when the pH is changed.
An indicator can provide exact pH if you are using the neutralization titration. Paper strip pH indicator are not an exact measurement but a high, medium, and low indication of acids and bases.
Sodium sulfate is typically colorless in universal indicator. Universal indicator is a pH indicator that changes color based on the pH of a solution, and sodium sulfate is a neutral compound that does not significantly affect the pH.
Red cabbage can be used as a pH indicator for a wide range of pH levels, showing different colors depending on the acidity or alkalinity of a substance. Similarly, beets can also be used as a pH indicator, turning different colors in acidic or basic solutions.
Bromothymol blue is the pH indicator used in the citrate test. It turns blue at an alkaline pH, indicating that citrate has been utilized by the bacteria.
The indicator that gives you the range of colors for different pH numbers is called universal indicator. It is a mixture of several indicators that changes color over a wide pH range.
Soap typically appears pink or red on a pH indicator because it is basic in nature.
pH range of indicator should be in the rapid pH gradient.
Hardness
indicator
This is a pH indicator.
A pH meter uses a probe and voltmeter to measure pH digitally. Universal indicator is a mix of indicators that change colour to indicate the pH of the solution. pH meters are accurate and will detect changes quickly, whereas universal indicator is slow to change colour to indicate pH change.