Question

Look at the diagram below. a buret filled with a base of known concentration is set up on a stand with a stopcock to drip into a flask containing acid of an unknown concentration. a small container of phenolphthalein is nearby. which best describes what is taking place in the diagram? the calibration of an acid is being completed with a base. a direct measurement of ph is taking place. an indirect measurement of ph is taking place. the final volume of an acid or base is being measured.

Answer 1

The best description of what's taking place is an indirect measurement of pH is taking place.

Option C is correct

The burette with base, flask with acid, and indicator (phenolphthalein), the setup points towards an indirect titration process to measure the pH of the acid solution.

The base is slowly added, and the indicator changes color at the endpoint when the equivalence point (neutral pH) is reached. By noting the volume of base used to reach this point, the unknown concentration of the acid can be calculated.