Chapter 9.1, Problem 5RQ

Interpretation Introduction

Interpretation:

The number of moles of oxygen react with 10.0 mole of sodium needs to be determined.

Concept Introduction:

Mole is the amount of the substance that contains the same number of particles or atoms or molecules. Molar mass is defined as an average mass of atoms present in the chemical formula. It is the sum of the atomic masses of all the atoms present in the chemical formula of any compound.

Answer to Problem 5RQ

2.5 moles of oxygen reacts with 10.0 moles of sodium.

Explanation of Solution

The chemical reaction is shown below:

  $\text{4Na}\text{+}{\text{O}}_{\text{2}}\to {\text{2Na}}_{\text{2}}\text{O}$

Moles of sodium = 10.0 moles

According to the reaction;

  $\begin{array}{l}{\text{4 moles of Na = 1 mol of O}}_{\text{2}}\hfill \\ \text{1 mol of Na =}\frac{\text{1}}{\text{4}}{\text{ mol of O}}_{\text{2}}\hfill \\ \begin{array}{l}\text{10 mol of Na =}\frac{\text{1}}{\text{4}}\text{×}\text{10}\text{mol}\text{of}{\text{O}}_{\text{2}}\\ \text{=}\text{2}\text{.5}\text{mol}\text{of}{\text{O}}_{\text{2}}\end{array}\hfill \end{array}$

Conclusion

Thus, 2.5 moles of oxygen reacts with 10.0 moles of sodium.