Question

carlos set up three full vials beside one another and added drops to see the surface tensions of three different liquids. which event could be a source of error?
a. the liquids that spilled over the edges could mix on the table.
b. the air temperature varied when someone opened a window.
c. the vials were made of the same material.
d. the vials were different shapes.

Explanation:

• Option A: Liquids mixing on the table does not affect the surface tension measurement of each liquid in the vial.
• Option B: Surface tension is affected by temperature. A change in temperature (due to opening a window) can cause an error in the surface tension measurement as surface - tension values are temperature - dependent.
• Option C: Vials made of the same material is a good control in the experiment as the interaction of the liquid with the vial material (which can affect surface tension) is consistent.
• Option D: The shape of the vial (if it is just a regular container shape) does not directly affect the surface tension of the liquid inside. Surface tension is a property of the liquid - air (or liquid - other gas) interface and is not influenced by the container's shape in a non - extreme, regular - container scenario.

Answer:

B. The air temperature varied when someone opened a window.