Question

For some jobs, “good enough” is good enough. That’s sometimes true in chemistry. More often, though, careful planning, calculations, measurement, and laboratory work are necessary to get the desired result. Imagine two tasks that would involve a chemical reaction of some sort. For one, measurement is not all that critical. For the other, careful stoichiometry and laboratory process is essential. Identify and describe two tasks (projects, operations, devices, etc.) that differ in this way.

Answer 1

For the first task, lighting a campfire can be used. Quantities of firestarter and kindling do not need to be precise. For the second task, the process of titration can be used. In a titration, the precise amount of a substance may be determined by adding a precise amount of a reactive species

Answer 2

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

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.