Universal indicator is a chemical solution that is used to determine the pH of a solution. pH is a measure of the acidity or basicity of a solution, with a range of 0 to 14. A pH of 7 is considered neutral, while pH values below 7 are acidic and values above 7 are basic or alkaline. Universal indicator is a mixture of several indicators that change color depending on the pH of the solution. In this article, we will explore the universal indicator color chart and how it is used to measure pH.
How Universal Indicator Works
Universal indicator is a mixture of several different indicators that change color at different pH levels. The most commonly used indicators in universal indicator are bromothymol blue, phenol red, and methyl red. Bromothymol blue changes from yellow to blue as the pH increases from acidic to basic, while phenol red changes from yellow to red. Methyl red changes from red to yellow as the pH increases from acidic to basic.
Universal Indicator Color Chart
The universal indicator color chart is a visual representation of the colors that the indicators in the solution change to at different pH levels. The chart usually shows a range of pH values from 0 to 14, with corresponding colors for each pH value. The colors on the chart can vary depending on the manufacturer, but the most commonly used colors are:
- Red: pH 0-3
- Orange: pH 3-5
- Yellow: pH 5-7
- Green: pH 7-9
- Blue: pH 9-12
- Purple: pH 12-14
It is important to note that the colors on the chart are not absolute, and can vary depending on the concentration of the solution and other factors. However, the chart provides a general guide to the pH of a solution based on the observed color.
How to Use Universal Indicator
To use universal indicator, a small amount of the solution is added to the solution being tested. The color change of the solution is then compared to the universal indicator color chart to determine the pH. It is important to ensure that the solution being tested is clean and free from any contaminants that could affect the pH measurement.
Conclusion
Universal indicator is a useful tool for measuring the pH of a solution. The color changes of the indicators in the solution can be compared to the universal indicator color chart to determine the pH of the solution. It is important to note that the color chart is not absolute and that the observed color can vary depending on the concentration of the solution and other factors. However, with proper use and interpretation, the universal indicator color chart can provide a reliable guide to pH measurement.
