Chapter 9, Problem 26QAP

Interpretation Introduction

Interpretation: The mass of ${\text{H}}_{\text{2}}\text{O}$ needed to completely react with 20.0 g of ${\text{PCl}}_{\text{3}}$ should be calculated.

Concept Introduction: The reaction between ${\text{PCl}}_{\text{3}}$ and ${\text{H}}_{\text{2}}\text{O}$ is as follows:

  ${\text{PCl}}_3\left(s\right)+3{\text{H}}_2\text{O}\left(l\right)\to {\text{H}}_{\text{3}}{\text{PO}}_{\text{3}}\left(aq\right)+3\text{HCl}\left(aq\right)$

From the above reaction, 1 mole of ${\text{PCl}}_{\text{3}}$ reacts with 3 moles of ${\text{H}}_{\text{2}}\text{O}$ to give 1 mole of ${\text{H}}_{\text{3}}{\text{PO}}_{\text{3}}$ and 3 moles of HCl. To calculate mass of ${\text{H}}_{\text{2}}\text{O}$ , number of moles of ${\text{H}}_{\text{2}}\text{O}$ should be calculated from number of moles of ${\text{PCl}}_{\text{3}}$ .