Question

The variation of pH during the titration of 0.5 N $N{a}_{2}C{O}_3$ with 0.5 N HCI is shown in the given graph, the following table indicates the colour and pH ranges of different indicators :

Indicator	Range of colour change	colour in acid	colour in base
Thymol blue	1.2 to 2.8	Red	Yellow
Bromocresol red	4.2 to 6.3	Red	Yellow
Bromothymol blue	6.0 to 7.6	Yellow	Blue
Cresolphethalain	8.2 to 9.8	Colourless	Red

Based on the graph and the table, which of the following statements are true?

• A. The first equivalence point can be detected by cresolphthalein
• B. The complete neutralisation can be detected by bromothymol blue
• C. The second equivalence point can be detected by bromocresol red
• D. The volume of HCI required for the first equivalence point is half the volume of HCI required for the second equivalence point

Answer 1

Answer: (A), (C), (D)

The correct options are
A The first equivalence point can be detected by cresolphthalein
C The second equivalence point can be detected by bromocresol red
D The volume of HCI required for the first equivalence point is half the volume of HCI required for the second equivalence point