An alkali is titrated against an acid with methyl orange as indicator. Which of the following is a correct combination-

Options

A. Base-Weak, Acid-Strong, End point- Colourless to pink
B. Base-Strong, Acid-Strong, End point-Pinkish red to yellow
C. Base-Weak , Acid-Strong, End point-Yellow to pinkish red
D. Base-Strong, Acid-Strong, End point-Pink to colourless

Explanation

The pH range for the colour change of methyl orange is 3.9-4.5. In the titration of weak base vs strong acid. the pH of the end point is less than 7. Thus for this kind of titration. m ethyl orange is the suitable indicator.