Chapter 11.2, Problem 24LC

Interpretation Introduction

Interpretation: To determine why the law of conservation of mass is not violated after the wood is burnt.

Concept Introduction: According to the law of conservation of mass, the mass can neither be created nor destroyed but is transformed from one form to another.

Answer to Problem 24LC

When wood burns, it transforms into ash or coal, neither of which has the same weight as the wood burned. Mass is transformed into heat and light.

Explanation of Solution

Because wood burns to generate carbon dioxide, gaseous water, and ash in addition to other products, the ash weighs far less than the original wood. Although they are not included in the ash mass, carbon dioxide and gaseous water also have mass; nonetheless, if we include all mass, then all masses are equal. Therefore, the conservation of mass law is not broken.