Answer: 1. Activity where measurement is not critical : Reading a pH // adding an indicator for a titration
2. Activity where measurement is essential: A Titration
Step-by-step explanation:
1. Reading a pH: When reading a pH from a sample, it´s not necessary to measure the amount of sample, but, to have enough just to place the electrode body .
Same happens when adding an indicator in a sample, it´s not necessary to quantify the amount of indicator, but only adding enough to watch the change of color when making a titration.
2. A titration : When making a titation is really important to measure strictly the volumen of the aliquot that will be titrated and measure the amount of titrant that will be necessary for the titration.