What is the Difference Between Methyl Orange and Phenolphthalein?

Methyl orange and phenolphthalein are both pH indicators used in titration techniques, but they have different color changes and pH ranges. Here are the main differences between the two:

1. Color Changes:

• Methyl orange turns red in acidic conditions and yellow in basic conditions.
• Phenolphthalein remains colorless in acidic conditions and turns pink in basic conditions.

1. pH Ranges:

• Methyl orange's color change occurs in the pH range of 3.1 to 4.4.
• Phenolphthalein's color change occurs in the pH range of 8.3 to 10.0.

1. Titration Concentrations:

• Methyl orange is used to determine the total hydroxide and half of the carbonate present in a solution during titration, typically at a pH of 5.1, 4.8, 4.5, or 3.7.
• Phenolphthalein is used to determine the total hydroxide and half of the carbonate present in a solution during titration to a pH of 8.3.

In summary, methyl orange is more suitable for detecting changes in pH in the acidic range, while phenolphthalein is more suitable for detecting changes in pH in the basic range. Both indicators are used in titration techniques, but their specific applications depend on the pH range of the solution being titrated.

Comparative Table: Methyl Orange vs Phenolphthalein

Methyl Orange and Phenolphthalein are both acid-base indicators used to determine the pH of a solution, but they have different color change characteristics and are used in different types of reactions. Here is a table comparing their differences:

Methyl Orange is used in reactions between strong acids and weak bases, as it changes color at the pH of the equivalence point. Phenolphthalein, on the other hand, is used in reactions between strong acids and strong bases or weak acids and weak bases, as its color change does not occur at the equivalence point.