Chapter 7, Problem 87CP

(a)

Interpretation Introduction

Interpretation : The number of moles of NaF in the tube of toothpaste should be calculated.

Concept Introduction : The molar mass of any compound is always the sum of atomic masses of atoms present in the compound. The relation between moles and mass can be expressed as:

  $\text{Moles = }\frac{\text{Mass}}{\text{Molar mass}}$

Mass percent composition can be given as:

  $\text{Mass percent of element =}\frac{\text{Mass of the element}}{\text{Molar mass of element}}\text{ x 100}$

(b)

Interpretation Introduction

Interpretation: The number of fluoride ions in the tube of toothpaste should be calculated.

Concept Introduction : The molar mass of any compound is always the sum of atomic masses of atoms present in the compound. The relation between moles and mass can be expressed as:

  $\text{Moles = }\frac{\text{Mass}}{\text{Molar mass}}$

Mass percent composition can be given as:

  $\text{Mass percent of element =}\frac{\text{Mass of the element}}{\text{Molar mass of element}}\text{ x 100}$

(c)

Interpretation Introduction

Interpretation : The mass of sodium ion should be calculated.

Concept Introduction : The molar mass of any compound is always the sum of atomic masses of atoms present in the compound. The relation between moles and mass can be expressed as:

  $\text{Moles = }\frac{\text{Mass}}{\text{Molar mass}}$

Mass percent composition can be given as:

  $\text{Mass percent of element =}\frac{\text{Mass of the element}}{\text{Molar mass of element}}\text{ x 100}$

(d)

Interpretation Introduction

Interpretation : The number of molecules of triclosan should be calculated.

Concept Introduction : The molar mass of any compound is always the sum of atomic masses of atoms present in the compound. The relation between moles and mass can be expressed as:

  $\text{Moles = }\frac{\text{Mass}}{\text{Molar mass}}$

Mass percent composition can be given as:

  $\text{Mass percent of element =}\frac{\text{Mass of the element}}{\text{Molar mass of element}}\text{ x 100}$

(e)

Interpretation Introduction

Interpretation : The mass percent composition of triclosan should be calculated.

Concept Introduction : The molar mass of any compound is always the sum of atomic masses of atoms present in the compound. The relation between moles and mass can be expressed as:

  $\text{Moles = }\frac{\text{Mass}}{\text{Molar mass}}$

Mass percent composition can be given as:

  $\text{Mass percent of element =}\frac{\text{Mass of the element}}{\text{Molar mass of element}}\text{ x 100}$