Chapter 19, Problem 37A

Interpretation Introduction

Interpretation:

The oxidation number of alkali and alkaline earth metals in their compounds is to be defined.

Concept introduction:

Oxidation number: It is defined as charge the atom would have if electrons are not shared but transfer completely.

Answer to Problem 37A

Oxidation number of alkali metals in their compounds=+1

Oxidation number of alkaline earth metals in their compounds=+2

Explanation of Solution

Every atom involved in redox reaction has an oxidation number.

There are some rules to assign oxidation number:

• For an atom in its elemental form, oxidation number=0
• For a monatomic ion, oxidation number=charge of ion
• The sum of oxidation number value for the atoms in a molecule equal to zero for neutral compound and equal to total charge if it is a polyatomic ion
• For group (I)A, oxidation number=+1 in all compounds
• For group (II)A, oxidation number=+2 in all compounds
• For fluorine, oxidation number=-1 in all compounds

Conclusion

Therefore alkali metals have oxidation number of +1 and alkaline earth metals of +2 in their compounds