Chapter 15, Problem 108A

Analyze both of the images in Figure 15.27 in terms ofpotential energy of position, chemical potential energy,kinetic energy, and heat.

Interpretation Introduction

Interpretation:

The two given images need to be described in terms of potential energy of position, chemical potential energy, kinetic energy, and heat.

Concept introduction:

The law of conservation of energy states that in a chemical or physical process, one form of energy disappears to form another form of the energy, there is no overall loss of energy.

Answer to Problem 108A

$\text{PE}+\text{KE}+\text{H}=\text{Constant}$

Explanation of Solution

According to first law of thermodynamics, whenever there occurs any physical or chemical change, one form of energy is converted into another form of energy or no loss of energy takes place.

In the given image 1, ice converts into liquid and vapor. The kinetic energy of ice molecule will increase and the potential energy will decrease.

$\text{PE}+\text{KE}+\text{H}=\text{Constant}$

In the given image 2, in combustion the kinetic energy will increase because the molecules will be in motion when the temperature increases.

$\uparrow \text{Temperature}\propto \uparrow \text{Kinetic}\text{energy}$

Here, potential energy is 0

$\begin{array}{c}\Delta \mathrm{H}=-ve\\ \text{Temeprature}=\text{Potential}\text{energy}+\text{Kinetic}\text{energy}\\ \text{Temeprature}=\text{0}+\text{Kinetic}\text{energy}\\ \text{Temeprature}=\text{Kinetic}\text{energy}\end{array}$

Conclusion

Potential and kinetic energy of a substance or reaction depends on composition of atoms, number and type of bonds.