Question

Acid/base indicator with a pK${}_a$ of $6.8$ is Bromothymol blue. During an acid base titration, at what approximate pH, will bromothymol blue undergo a color change?

• A. $1$
• B. $3$
• C. $5$
• D. $7$
• E. $13$

Answer 1

Answer: (D)

$7$

Acid/base indicator with a pKa of $6.8$ is Bromothymol blue. During an acid base titration, the approximately pH at which bromothymol blue will undergo a color change is $7$.
The pH range for colour change is pKa $\pm 1$. It is around $5.8$ to $7.8$.