Chapter 6.6, Problem 2QQ

Interpretation Introduction

Interpretation:

If the chemical equation $Al+O_2\stackrel{}{\to }A{l}_2{O}_3$ is balanced correctly, the expreseeion that occurs has to be chosen from the given options.

Concept Introduction:

Statement that uses chemical symbols and formulas instead of words in order to describe the changes that takes place in a chemical reaction is known as chemical equation.  Reactants are the substances that are present in starting of the chemical reaction and it is entered in left side of the chemical equation.  Products are the substance that is obtained from the reactants as a final outcome of the chemical reaction and it is entered in right side of the chemical equation.  In order to write a chemical equation four conventions are used and they are,

• Correct formulas of the reactants are written in left side of chemical equation.
• Correct formulas of products are written in right side of chemical equation.
• An arrow is placed between reactants and products which point towards the products.
• If two or more substances are present in reactant and product, plus sign is used to separate them.

Balanced chemical equation is the one that has equal number of atoms of each element that is involved in the chemical reaction on both sides of the chemical equation.  An unbalanced chemical equation can be balanced by adding coefficients to the equation.  It is a number that is placed in left side of the chemical formula so that it changes the amount only and not the identity.