Chapter 15, Problem 67A

Interpretation Introduction

Interpretation: The reason for water to have a maximum density at $4{}^{\text{o}}\text{C}$ needs to be explained.

Concept Introduction:

Density of any substance is equal to mass per unit volume. Thus, density is inversely proportional to volume. Any substance has maximum density when its volume is minimum.

Explanation of Solution

At $0{}^{\text{o}}\text{C}$ , water exists as a cage-like structure. Due to this, its volume increases. As a result, density decreases. When the temperature is increased or raised to $4{}^{\text{o}}\text{C}$ , the value of density is maximum because the cage-like structure begins to break and come closer.

Above $4{}^{\text{o}}\text{C}$ , water exists in liquid form thus, water has its maximum density at $4{}^{\text{o}}\text{C}$ .