Chapter 7.2, Problem 10PP

Interpretation Introduction

Interpretation:

The formation of ionic compound from elements Aluminum and sulfur needs to be explained.

Concept introduction:

Chemical compounds are formed when the atoms, ions or molecules of two substances are attracted towards each other forming a chemical bond. This bond can be electrostatic when two oppositely charged ions are attracted towards each other and this bond is said to be ionic bond.

Answer to Problem 10PP

2 Aluminum atoms will lose 6 electrons which is gained by 3 of sulfur atoms to form ionic compound ${\text{Al}}_2{\text{S}}_3$

Explanation of Solution

The formation of Aluminum Sulfide is when Aluminum atoms interact with sulfur atom.

The electronic configuration of Aluminum is ${\text{1s}}^{\text{2}} {\text{2s}}^{\text{2}} {\text{2p}}^{\text{6}} {\text{3s}}^{\text{2}} {\text{3p}}^{\text{1}}$ or $\left[\text{Ne}\right]{\text{3s}}^2{\text{3p}}^1$

Aluminum atom has 3 outermost electrons which can be lost easily as its force of attraction with the nucleus is less and hence becomes a positive ion.

Figure 1

The electronic configuration of sulfur is ${\text{1s}}^{\text{2}} {\text{2s}}^{\text{2}} {\text{2p}}^6 {\text{3s}}^2 {\text{3p}}^{\text{4}}$ or $\left[\text{Ne}\right]{\text{3s}}^2{\text{3p}}^4$

Sulfur atom has 2 half filled shells of p orbital. To fill up the half filled shell, it can take up 2 electrons to become a sulfide anion.

Figure 2

When Aluminum looses electrons it becomes positively charged and sulfur atom which gains electrons will become negatively charged. Due to forces of attraction, it forms ionic compound.

Here 2 Aluminum atoms will bond with 3 of Sulfur atoms to form ionic compound ${\text{Al}}_2{\text{S}}_3$

Conclusion

2Aluminum atoms will lose 6 electrons which is gained by 3 of sulfur atoms to form ionic compound ${\text{Al}}_2{\text{S}}_3$