Chapter 2, Problem 121A

Interpretation Introduction

Interpretation:

The layering of the liquids needs to be predicted if they are carefully poured into a large graduated cylinder.

Concept introduction:

Density of a sample of matter or an object is equal to the mass of the sample divided by the volume of the sample.

$\text{Density}=\frac{\text{Mass}}{\text{Volume}}$

The liquid with lowest density forms the first layer and the liquid with highest density forms the last layer.

Answer to Problem 121A

The order of the liquids form bottom to the top will be Liquid D, Liquid C, Liquid B and Liquid A.

Explanation of Solution

Given Information:

The four graduated cylinders contain different liquid i.e. A, B, C and D. The mass and volume of each liquid is given as follows:

Liquid A: $\text{mass}=\text{18}\text{.5}\text{g};\text{volume}=\text{15}\text{.0}\text{mL}$

Liquid B: $\text{mass}=\text{12}\text{.8}\text{g};\text{volume}=\text{10}\text{.0}\text{mL}$

Liquid C: $\text{mass}=20.\text{5}\text{g};\text{volume}=\text{12}\text{.0}\text{mL}$

Liquid D: $\text{mass}=\text{16}\text{.5}\text{g};\text{volume}=8.\text{0}\text{mL}$

Calculation:

For the determination of layering of liquids, the density of each liquid must be calculated by dividing the mass of the liquid by its volume.

$\begin{array}{c}\text{Density}\text{of}\text{Liquid}\text{A}=\frac{\text{18}\text{.5}\text{g}}{\text{15}\text{.0}\text{mL}}\\ =1.23\text{g/mL}\\ \text{Density}\text{of}\text{Liquid}\text{B}=\frac{12.8\text{g}}{\text{10}\text{.0}\text{mL}}\\ =1.28\text{g/mL}\\ \text{Density}\text{of}\text{Liquid}\text{C}=\frac{\text{20}\text{.5}\text{g}}{\text{12}\text{.0}\text{mL}}\\ =1.71\text{g/mL}\\ \text{Density}\text{of}\text{Liquid}\text{D}=\frac{\text{16}\text{.5}\text{g}}{\text{8}\text{.0}\text{mL}}\\ =2.1\text{g/mL}\end{array}$

The liquid whose density is highest will be at the bottom of the large graduated cylinder while the liquid having least density will be present at the top. Thus, the order of the liquids form bottom to the top will be Liquid D, Liquid C, Liquid B and Liquid A.

Conclusion

The order of the liquids form bottom to the top will be Liquid D, Liquid C, Liquid B and Liquid A.