Chapter ST, Problem 13PQ

Interpretation Introduction

Interpretation:

Number of atoms in $9\text{g}$ of $\text{Al}$ has to be determined.

Concept Introduction:

Mole is S.I. unit. The number of moles is calculated as ratio of mass of compound to molar mass of compound.

Molar mass is sum of total mass in grams of all atoms that make up mole of particular molecule that is mass of 1 mole of compound. The S.I unit is $\text{g/mol}$.

The expression to relate number of moles, mass and molar mass of compound is as follows:

  $\text{Number of moles}=\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

When atoms and molecules are too small to count then they are expressed in terms of Avogadro’s number. Mole can be defined as a unit that represents $6.02\times {10}^{23}$ particles of same matter.