CAIE IGCSE Chemistry Alkali Indicator Colours

Practise recalling indicator colours in alkaline solution and distinguishing litmus, methyl orange and thymolphthalein results without mixing their endpoints.

Exam points

state that red litmus changes to blue and blue litmus remains blue in an alkaline solution
state that methyl orange appears yellow when it is added to an alkaline solution
state that thymolphthalein is blue in alkali but colourless in acidic solution

[Maximum number: 1]

Solid sodium hydroxide is a base which dissolves to form an aqueous solution, NaOH(aq).

State the colour of thymolphthalein in NaOH(aq).

All question bank results loaded

7.1.5—Alkalis in terms of their effect on question 1