Chapter 21, Problem 84GQ

(a)

Interpretation Introduction

Interpretation: To draw the structure of ${\left[{\text{P}}_{\text{4}}{\text{O}}_{\text{13}}\right]}^{-n}$. The charge on ${\left[{\text{P}}_{\text{4}}{\text{O}}_{\text{13}}\right]}^{-n}$ compound and ionizable hydrogen atoms should have the completely protonated acid is to be stated.

Concept introduction: polyphosphoric acids have linear chains and hence are called linear polyphosphoric acids. In the structure of polyphosphate ion, ${\left[{\text{P}}_n{\text{O}}_{3n+1}\right]}^{-\left(n+2\right)}$ the linear chains are obtained by uniting ${\text{PO}}_{\text{4}}$ tetrahedrons together through one, two or more O- atoms.

Polymetaphosphates are the salts of polymetaphosphoric acids. These acids are represented by the general formula ${\text{H}}_{\text{n}}{\text{P}}_{\text{n}}{\text{O}}_{\text{3n}}$. It can be obtained by eliminating n moles of ${\text{H}}_{\text{2}}\text{O}$ from n moles of ${\text{H}}_{\text{3}}{\text{PO}}_{\text{4}}$.

(b)

Interpretation Introduction

Interpretation: To draw the structure of ${\left[{\text{P}}_{\text{4}}{\text{O}}_{\text{12}}\right]}^{-n}$. The charge on ${\left[{\text{P}}_{\text{4}}{\text{O}}_{\text{12}}\right]}^{-n}$ compound and ionizable hydrogen atoms should have the completely protonated acid is to be stated.

Concept introduction: polyphosphoric acids have linear chains and hence are called linear polyphosphoric acids. In the structure of polyphosphate ion, ${\left[{\text{P}}_n{\text{O}}_{3n+1}\right]}^{-\left(n+2\right)}$ the linear chains are obtained by uniting ${\text{PO}}_{\text{4}}$ tetrahedrons together through one, two or more O- atoms.

Polymetaphosphates are the salts of polymetaphosphoric acids. These acids are represented by the general formula ${\text{H}}_{\text{n}}{\text{P}}_{\text{n}}{\text{O}}_{\text{3n}}$. It can be obtained by eliminating n moles of ${\text{H}}_{\text{2}}\text{O}$ from n moles of ${\text{H}}_{\text{3}}{\text{PO}}_{\text{4}}$.