Question

A graduated cylinder contains three liquids \(\mathrm{A}, \mathrm{B}\), and \(\mathrm{C}\), which have different densities and do not mix: mercury \((\mathrm{D}=13.6 \mathrm{~g} / \mathrm{mL})\), vegetable oil \((\mathrm{D}=0.92 \mathrm{~g} / \mathrm{mL})\), and water \((\mathrm{D}=1.00 \mathrm{~g} / \mathrm{mL}) .\) Identify the liquids \(\mathrm{A}, \mathrm{B}\), and \(\mathrm{C}\) in the cylinder.

Short answer

Liquid \(\text{C}\) is Mercury, Liquid \(\text{B}\) is Water, Liquid \(\text{A}\) is Vegetable Oil.

Step-by-step solution

Understand the Problem

The problem gives you three liquids: mercury, vegetable oil, and water. You need to identify which of these liquids corresponds to \(\text{A}\), \(\text{B}\), and \(\text{C}\) based on their densities.

Recall Density Values

Densities are given as: Mercury: \(\text{D}=13.6 \, \mathrm{g/mL}\) Vegetable Oil: \(\text{D}=0.92 \, \mathrm{g/mL}\) Water: \(\text{D}=1.00 \, \mathrm{g/mL}\)

Arrange Liquids by Density

Since the liquids do not mix and have different densities, they will layer in the cylinder, with the most dense liquid at the bottom and the least dense at the top. Hence, the order from bottom to top is Mercury, Water, Vegetable Oil.

Identify Each Liquid

Based on the order:- Liquid \(\text{C}\) (bottom) is Mercury \(\text{D}=13.6 \, \mathrm{g/mL}\)- Liquid \(\text{B}\) (middle) is Water \(\text{D}=1.00 \, \mathrm{g/mL}\)- Liquid \(\text{A}\) (top) is Vegetable Oil \(\text{D}=0.92 \, \mathrm{g/mL}\)

Key concepts

liquid density

Density is a measure of how much mass is contained in a given volume. It is usually expressed in \[\text{grams per milliliter (g/mL)}\].
The formula to calculate density is: \[ \text{Density} = \frac{\text{Mass}}{\text{Volume}} \].
In the context of the given exercise, the ability of a liquid to float or sink in another liquid is determined by its density.
A liquid with a higher density will sink in a liquid with a lower density.
This is why in our example, mercury (with a density of 13.6 g/mL) sinks to the bottom of the graduated cylinder,
while vegetable oil (with a density of 0.92 g/mL) stays on top.

graduated cylinder

A graduated cylinder is a common laboratory instrument used to measure the volume of liquids accurately.
It is usually made of glass or plastic and has volume markings along its length.
The design of the graduated cylinder allows for precise measurements, which are essential in experiments where accuracy is critical.
When observing the layering of liquids in a graduated cylinder, one must note the volume each liquid occupies without mixing.
This makes it easier to determine which liquid corresponds to a specific volume marking based on their densities.

layering of liquids

When pouring liquids with different densities into a graduated cylinder, they will naturally form layers.
The key principle here is that liquids with higher densities sink below those with lower densities.
In our exercise, the order from bottom to top is mercury, water, and vegetable oil, reflecting their respective densities.

• Mercury, at 13.6 g/mL, will be the bottommost layer.
• Water, at 1.00 g/mL, will sit in the middle.
• Vegetable oil, at 0.92 g/mL, will form the topmost layer.

Knowing this principle can help you identify unknown liquids in mixed scenarios by observing their order of layers.