Chapter 3, Problem 3.2P

(a)

Interpretation Introduction

Interpretation:

The moles of $\text{C}$ atoms in $\text{1 mol}$ of sucrose $\left({\text{C}}_{\text{12}}{\text{H}}_{\text{22}}{\text{O}}_{\text{11}}\right)$ are to be determined.

Concept introduction:

The SI unit for amount of substance is $\text{mol}$. One mole is defined as the amount of substance that contains the same number of entities such as molecules, ions, atoms as the number of atoms in $12\text{ g}$ of $\text{C-12}$.

The amount of an element can be calculated from the given amount of compound and the moles of that element present in one mole of compound. The molecular formula of the compound tells the number of atoms of each element. The road map to calculate the moles of an element in a compound is as follows:

The expression to calculate the amount of an element in a compound is as follows:

$\text{Amount }\left(\text{mol}\right)\text{of element}=\left(\text{amount of compound}\left(\text{mol}\right)\right)\left(\frac{\begin{array}{l}\text{moles of element in}\\ \text{molecular formula}\end{array}}{1\text{ mol compound}}\right)$

(b)

Interpretation Introduction

Interpretation:

The number of $\text{C}$ atoms in $\text{2 mol}$ of sucrose $\left({\text{C}}_{\text{12}}{\text{H}}_{\text{22}}{\text{O}}_{\text{11}}\right)$ is to be determined.

Concept introduction:

The SI unit for amount of substance is $\text{mol}$. One mole is defined as the amount of substance that contains the same number of entities such as molecules, ions, atoms as the number of atoms in $12\text{ g}$ of $\text{C-12}$. This number is called Avogadro’s number. The value of Avogadro’s number is $\text{6}\text{.022}\times {\text{10}}^{23}\left(\text{entitites/mol}\right)$.

The number of an atom of an element can be calculated from the given amount of compound, the moles of that element present in one mole of the compound and the Avogadro’ number.

The road map to calculate the number of atoms of an element in a compound is as follows:

The expression to calculate the number of atoms of an element in a compound is as follows:

$\text{Number of atoms}=\left(\begin{array}{l}\text{amount of}\\ \text{compound}\\ \left(\text{mol}\right)\end{array}\right)\left(\frac{\begin{array}{l}\text{moles of element in}\\ \text{molecular formula}\end{array}}{1\text{ mol compound}}\right)\left(\frac{6.022\times {10}^{23}\text{ atoms}}{1\text{ mol}}\right)$