Question

Which of the following is an example of qualitative observation?Select one of the options below as your answer:. A. Joseph is observing the color difference in the reaction mixture of each of the test samples to see what types of proteins are present in them.. B. Joseph is measuring the color of the reaction mixture colorimetrically to see the concentration of proteins in the sample.. C. Joseph is observing the color of the reaction mixture to see whether proteins are present in the given solution..

Answer 1

The probable answer here is letter C. 
Letter A can't be the answer since when we talk about color differences there is a "difference involve. So it is observing the magnitude of the change in color. 
Letter B can't be the answer since when we involve colorimetry, there is a corresponding values to these readings. This is actually a quantitative test. 
Letter C is the answer since, we are just observing if there is a certain color appears after the reaction takes place. 

Answer 2

Answer : Option C) Joseph is observing the color of the reaction mixture to see whether proteins are present in the given solution.

Explanation :

An example of qualitative observation is the one where one uses the five senses to identify the changes in the reaction.

Here, when Joseph is studying a reaction mixture he is trying to observe a color change which will confirm that there is proteins present in the reaction mixture or not If there is a color change observed then it will confirm the presence of proteins.

Usually qualitative observations are those which can be easily predicted by using five senses.