Chapter 8, Problem 8.90QP

Interpretation Introduction

Interpretation: the mass of ${\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}$ formed and ${\text{KClO}}_{\text{3}}$ decomposed should be determined when $\text{15g}$ of iron sample is used and 17.9g of $\text{Fe}$ and ${\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}$ are produced in the given process.

Concept introduction:

• Balanced chemical equation of a reaction is written according to law of conservation of mass.
• Equation for Number of moles of a substance, from its given mass is,

$\text{Number of moles}\text{=}\frac{\text{Given}\text{mass}}{\text{Molecular}\text{mass}}$

• Equation for Number of grams of a substance from its number of moles is,

$\text{Number of moles}\text{×}\text{Molecular}\text{mass in grams}\text{=}\text{Number}\text{of}\text{grams}$

• Mole ratio between the reactant and a product of a reaction are depends upon the coefficients of reactant and product in a balanced chemical equation.