Chapter 3, Problem 107A

Interpretation Introduction

Interpretation:

Whether the production of charcoal from dry distillation of wood is a chemical or physical change needs to be determined.

Concept introduction:

Charcoal is a hard, porous form of carbon which is black in color. It is similar to coal and can be used as a fuel. Charcoal, in the form of sticks, is used for drawing purposes. Coke, soot and carbon black are forms of charcoal.

Answer to Problem 107A

The production of charcoal by dry distillation of wood is a chemical change.

Explanation of Solution

Any change thereby altering a substance without changing its composition is called a physical change. In contrast, a process in which one or more substances undergo a change resulting in the formation of new substances is termed as a chemical change. The new substances (products) have different compositions and properties when compared to the starting substances (reactants).

In the process of dry distillation, solid materials are heated to very high temperatures to give gaseous products. These gaseous products may, then, condense into solids or liquids.

When wood is subjected to a high temperature of 270°C, it begins to carbonize, and in the absence of air, it results in the formation of charcoal. This process is also called pyrolysis, and in case of charcoal specifically, it is called charcoal burning.

The production of charcoal from dry distillation of wood is a chemical change because of change in composition of reactants(wood) and products(charcoal and other gaseous substances). New substances with differing compositions are formed as compared to the reactants initially used.

Conclusion

Hence, the production of charcoal using the process of dry distillation of wood is a chemical change.