Chapter 10, Problem 4STP

Interpretation Introduction

Interpretation: An exothermic process needs to be determined.

Concept introduction: Thermodynamics is the study of energy. The law of conservation of energy is also called the first law of thermodynamics.

The first law of thermodynamics is given as,

  $\text{ΔE}\text{=}\text{q}\text{+}\text{w}$

Here, $\text{Δ}$ is the change in the function that follows,

q is the heat and,

w is the work done.

Answer to Problem 4STP

A is the correct option.

Explanation of Solution

An exothermic process is a process where energy flows out of the given system into the surrounding. For example, in the combustion of a match, energy flows out of the system as heat.

Endothermic process is a process in which energy flows from the surroundings into the system. For example, Water boils to form steam.

Therefore, candle wax melting is a exothermic reaction as heat is released to the surrounding in this process.

Conclusion

In option B, C and D there is no flow of heat from the system to the surrounding. Therefore, option B, C and D are incorrect.