Chapter U1.25, Problem 3E

Interpretation Introduction

Interpretation:

A substance that is soluble in water and conducts electricity needs to be described.

Concept introduction:

There are millions of substances in the environment around us. It is very difficult to identify all these substances. Therefore, it is important to arrange substances into general categories by considering two properties: solubility and conductivity.

Answer to Problem 3E

A substance that is soluble in water and conducts electricity must be made of a metal element and a nonmetal element. Such substances are called ionic compounds. They will conduct electricity only when dissolved in water. Only metal substances will not dissolve in water although they will conduct electricity. Dry ionic solids will not conduct electricity.

Explanation of Solution

Two major properties of substances based on which they can be sorted into various categories are:

1. Solubility: Those which can dissolve in water and form aqueous solution are called soluble and those which do not dissolve in water are called insoluble.
2. Conductivity of electricity -Some substances can allow flow of electricity through them. Such substances are called conductors.

The substances which are soluble in water and conduct electricity are made up of one metal component and one nonmetal component. Such compounds are called ionic compounds. Ionic compounds conduct electricity only when they are dissolved in water as the ions are free to move in solution. In dry state they do not conduct electricity as ions are held together in fixed positions and cannot move around freely.

Conclusion

Ionic compounds conduct electricity in solution form. They are made of a metal element and a nonmetal element.