Question

why does the procedure use a graduated cylinder and not simply have you put 2 ml of solution directly into the test tube?
one objective of this lab is to successfully transfer liquids.
biuret reagent will only work in a graduated cylinder.
accuracy is important in the laboratory. there is no way to accurately put 2 ml into a test tube without first measuring 2 ml in the graduated cylinder.

Explanation:

• Analyzing the first option: Lab objectives often include developing practical skills like liquid transfer, and using a graduated cylinder to measure and transfer 2 mL to a test tube helps practice this skill.
• The second option is incorrect because Biuret reagent is used in test tubes for protein tests, not restricted to graduated cylinders.
• The third option is incorrect as while accuracy is important, it is possible to use other volumetric tools (like pipettes) to accurately add 2 mL to a test tube, so the reasoning about "no way" is flawed.

Answer:

A. One objective of this lab is to successfully transfer liquids.