Methyl Red Solution

Methyl Red Solution Dissolve 50 mg of methyl red in a mixture of 1.86 mL of 0.1m sodium hydroxide and 50 mL of ethanol (96%) and add sufficient water to produce 100 mL.

Complies with the following tests.

Sensitivity A mixture of 0.1 mL of the solution, 100 mL of carbon dioxide-free water and 0.05 mL of 0.02m hydrochloric acid VS is red. Not more than 0.1 mL of 0.02m sodium hydroxide VS is required to change the colour of the solution to yellow.

Colour change pH 4.4 (red) to pH 6.0 (yellow).