Chapter 7, Problem 10A

Interpretation Introduction

Interpretation: The unbalanced chemical equation for the reaction of burning of propane in oxygen gas to produce carbon dioxide gas, water vapor and heat should be determined.

Concept Introduction: An unbalanced reaction is that chemical reaction in which the number of atoms of each element in the product side and on reactant side are not equal.

Answer to Problem 10A

The unbalanced chemical equation is:

  ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}\left(\text{g}\right){\text{ + O}}_{\text{2}}\left(\text{g}\right)\to {\text{ CO}}_{\text{2}}\left(\text{g}\right){\text{ + H}}_{\text{2}}\text{O}\left(\text{g}\right)+\text{ heat}$

Explanation of Solution

The molecular formula for propane gas is ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}$ .

The molecular formula for oxygen gas is ${\text{O}}_{\text{2}}$ .

The molecular formula for carbon dioxide gas is ${\text{CO}}_{\text{2}}$ .

The molecular formula for water is ${\text{H}}_{\text{2}}\text{O}$ .

The physical state of the reactants and products are shown by writing the symbols after each reactant and product in the reaction. The symbol “l” represents liquid, “aq” represents aqueous, “s” represents solid, and “g” represents gas.

The reaction of burning of propane in oxygen gas to produce carbon dioxide gas, water vapor and heat is written as:

  ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}\left(\text{g}\right){\text{ + O}}_{\text{2}}\left(\text{g}\right)\to {\text{ CO}}_{\text{2}}\left(\text{g}\right){\text{ + H}}_{\text{2}}\text{O}\left(\text{g}\right)+\text{ heat}$

This reaction is not balanced as:

The number of mol of $\text{C}$ on reactant side is 3 and on product side is 1, the number of mol of $\text{H}$ on reactant side is 8 and on product side is 2 and the number of mol of $\text{O}$ on reactant side is 2 and on product side is 3.

Conclusion

The unbalanced chemical equation is:

  ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}\left(\text{g}\right){\text{ + O}}_{\text{2}}\left(\text{g}\right)\to {\text{ CO}}_{\text{2}}\left(\text{g}\right){\text{ + H}}_{\text{2}}\text{O}\left(\text{g}\right)+\text{ heat}$