Chapter 4, Problem 3A

Interpretation Introduction

Interpretation: The positive and negative ion that comprise ionic compound is to be identified.

Concept introduction: Elements are classified as metals and non metals on basis of various physical and chemical properties. Metals can easily release electrons and non metals can easily take electrons to attain stability in configuration and as a result cations and anions are formed.

Metal and non metals come closer to from binary ionic compounds which can be of 3 types:

• Type I binary ionic compound: which have metal ions that can form only 1 type of ion.
• Type II binary ionic compound: contains metal ions that can form more than 1 type of ions.
• Type III binary ionic compound: contains only non metal ions.

Answer to Problem 3A

Ionic compound comprise of positively charged ions called cations and negatively charged ions called anions.

So, first blank is filled by cations and second blank is filled by anions.

Explanation of Solution

Metals form electropositive ions called cations by the process of oxidation that is loss of electron due to low ionization energy associated to them. Ionization process of metal can be shown as follows:

  $\text{M}\to {\text{M}}^{\text{n+}}+{\text{ne}}^{-}$

Where,

  $\text{M}$ is metal.

  ${\text{M}}^{\text{n+}}$ is metal ion

  $\text{n}$ is oxidation state of metal ion or number of electron lost.

Non metals form electronegative ions called anions by the process of reduction that is gain of electron due to very high ionization energy associated to them. Ionization process of non-metal can be shown as follows:

  ${\text{M}}^{\text{n+}}+{\text{ne}}^{-}\to \text{M}$

Where,

  $\text{M}$ is non-metal.

  ${\text{M}}^{\text{n+}}$ is non- metallic ion

  $\text{n}$ is oxidation state of non-metallic ion or number of electron gain.

Conclusion

Ionic compound comprise of positively charged ions called cations and negatively charged ions called anions.

So, first blank is filled by cations and second blank is filled by anions.