Bromthymol Blue

Recipe

Aqueous version

Add 0.1g Bromthymol blue into 16ml of 0.01N NaOH

Mix in a mortar or small tube

Dilute to 250ml with distilled water

Use 5 drops in 10ml of test solution

Alcohol version

Add 0.5g of Bromthymol blue into 500ml of 95% ethanol and dissolve

Add 500ml of distilled water

Filter and store at room temperature