Question

valerie wants to examine the properties of a thick liquid but is finding it difficult to pour the liquid into a beaker. she needs to finish her investigation before the end of class. which method will allow her to pour the liquid easily?

• boiling the liquid vigorously
• mixing the liquid with another solution
• applying heat to the liquid
• placing the liquid in the refrigerator

Explanation:

Identify the physical property

The problem describes a "thick liquid" that is difficult to pour. The resistance of a fluid to flow is known as viscosity. A thick, slow-pouring liquid has high viscosity. To make the liquid pour more easily, we need to decrease its viscosity.

Analyze the effect of temperature

Using the Viscosity and Temperature knowledge point, we know that for most liquids, viscosity decreases as temperature increases. Heating the liquid gives its molecules more kinetic energy, allowing them to overcome intermolecular forces and slide past each other more easily, which makes the liquid thinner and easier to pour.

Evaluate the given options

• boiling the liquid vigorously: This would cause a phase change to gas, which would prevent Valerie from examining the properties of the liquid itself.
• mixing the liquid with another solution: This would alter the chemical composition and properties of the original liquid, ruining the investigation.
• applying heat to the liquid: This increases the temperature, reducing viscosity and making it easier to pour without changing its chemical identity.
• placing the liquid in the refrigerator: This decreases the temperature, which increases viscosity and makes the liquid even thicker and harder to pour.

Select the best method

Applying heat to the liquid is the most effective and safe method to temporarily lower its viscosity so it can be poured easily into the beaker.

Answer:

• boiling the liquid vigorously
• mixing the liquid with another solution
• applying heat to the liquid (Correct answer)
• placing the liquid in the refrigerator