Chapter U5, Problem 10STP

Interpretation Introduction

Interpretation:

The balanced chemical equation for combustion reaction needs to be determined.

Concept introduction:

A chemical change can be defined as the conversion of one substance to another by making and breaking of chemical bonds.

Reactant molecules involve in chemical reaction and form new products. Chemical reactions can be classified as synthesis reaction, decomposition reaction, Redox reaction, displacement reactions, etc.

Answer to Problem 10STP

Option (B) is correct.

Explanation of Solution

Reason for correct option: Combustion reaction can be defined as the chemical reaction in which substance will react with excess of oxygen to form carbon dioxide and water as the final products. These are exothermic reactions as they release a large amount of energy in the form of heat.

In the given reactions,(B) is balance combustion reaction of ${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}{\text{O}}_{\text{2}\left(\text{l}\right)}$ :

${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}{\text{O}}_{\text{2}\left(\text{l}\right)}{\text{ + 2 O}}_{\text{2(g)}}\stackrel{}{\to }{\text{ 2 CO}}_{\text{2(g)}}{\text{ +2 H}}_{\text{2}}{\text{O}}_{\text{(g)}}$

Conclusion

Reasons for incorrect options:

Reaction (a) is not a balanced chemical reaction as number of O atoms is not the same at both sides.

Reaction (c) and (d) are oxidation reactions of Li and Mg to form their respective oxides.