Question

Andrea is performing an experiment in which she needs to know when a strong acid is present. She is not sure which indicator to use, so she looks up the following table in her science textbook. Indicator pH range thymol Blue 1.2 - 2.8 phenol Red 6.4 - 8.0 phenolphthalein 8.0 - 10.0 trinitrobenzoic acid 12.0 - 13.4 According to the textbook, which indicator should Andrea use? Hint: Neutral substances have a pH of 7. Acids have a pH that is less than 7, and bases have a pH that is greater than 7. A. trinitrobenzoic acid B. phenol Red C. phenolphthalein D. thymol Blue

Answer 1

La opción correcta es la D: Azul de timol

Andrea en su experimento debe utilizar azul de timol por cuanto es el indicador con el rango de pH más bajo (1.2 – 2.8) que corresponde a los ácidos más fuertes.  

The correct option is D: Thymol blue

Andrea in her experiment should use thymol blue because it is the indicator with the lowest pH range (1.2 - 2.8) that corresponds to the strongest acids.