Chapter 1, Problem 1.87EP

(a)

Interpretation Introduction

Interpretation:

Among the given molecules, number of molecules that contain four or fewer atoms present in the mixture has to be given.

Concept Introduction:

The composition of a chemical compound can be presented in a very precise was with the use of chemical formula.  Chemical formula uses chemical symbols of the elements that is present in the compound and numerical subscripts that represent how many number of atoms of each element is present in the compound.

Answer to Problem 1.87EP

In the given mixture of five molecules, two kinds of molecules contains four or fewer atoms in it.

Explanation of Solution

Given molecules in mixture are $N_2,N_2{H}_4,N{H}_3,C{H}_4,andC{H}_{3}Cl$.

Number of atoms in $N_2$:  As this molecule has a subscript “2”, the total number of atoms in $N_2$ is two.

Number of atoms in $N_2{H}_4$:  The total number of atoms is present in molecule is by summing up the subscript.  The total number of atoms in $N_2{H}_4$ is 6 atoms.

Number of atoms in $N{H}_3$:  The total number of atoms is present in molecule is by summing up the subscript.  The total number of atoms in $N{H}_3$ is 4 atoms.

Number of atoms in $C{H}_4$:  The total number of atoms is present in molecule is by summing up the subscript.  The total number of atoms in $C{H}_4$ is 5 atoms.

Number of atoms in $C{H}_{3}Cl$:  The total number of atoms is present in molecule is by summing up the subscript.  The total number of atoms in $C{H}_{3}Cl$ is 5 atoms.

From the above number of atoms present in each and every molecule, the atoms that contains four or fewer atoms are $N_{2}andN{H}_3$.  Two molecules are present with four or fewer atoms.

(b)

Interpretation Introduction

Interpretation:

The different kind of atoms that is present in the mixture has to be given.

Concept Introduction:

The composition of a chemical compound can be presented in a very precise was with the use of chemical formula.  Chemical formula uses chemical symbols of the elements that is present in the compound and numerical subscripts that represent how many number of atoms of each element is present in the compound.

Answer to Problem 1.87EP

Four kinds of atoms are present in the mixture.

Explanation of Solution

Given molecules in mixture are $N_2,N_2{H}_4,N{H}_3,C{H}_4,andC{H}_{3}Cl$.

Looking into the molecules in the given mixture, it is found that there are four kind of atoms present in the given molecules and they are $N,C,H,andCl$.

(c)

Interpretation Introduction

Interpretation:

The total number of atoms that is present in the mixture that contains five molecules of each component has to be given.

Concept Introduction:

The composition of a chemical compound can be presented in a very precise was with the use of chemical formula.  Chemical formula uses chemical symbols of the elements that is present in the compound and numerical subscripts that represent how many number of atoms of each element is present in the compound.

Answer to Problem 1.87EP

There are a total of 110 atoms present.

Explanation of Solution

Given molecules in mixture are $N_2,N_2{H}_4,N{H}_3,C{H}_4,andC{H}_{3}Cl$.

Number of atoms in $N_2$:  As this molecule has a subscript “2”, the total number of atoms in $N_2$ is two.

Number of atoms in $N_2{H}_4$:  The total number of atoms is present in molecule is by summing up the subscript.  The total number of atoms in $N_2{H}_4$ is 6 atoms.

Number of atoms in $N{H}_3$:  The total number of atoms is present in molecule is by summing up the subscript.  The total number of atoms in $N{H}_3$ is 4 atoms.

Number of atoms in $C{H}_4$:  The total number of atoms is present in molecule is by summing up the subscript.  The total number of atoms in $C{H}_4$ is 5 atoms.

Number of atoms in $C{H}_{3}Cl$:  The total number of atoms is present in molecule is by summing up the subscript.  The total number of atoms in $C{H}_{3}Cl$ is 5 atoms.

The total number of atoms that is present in mixture which contains one molecule of each component can be found by summing up the number of atoms in all molecules.  This gives the total number of atoms as 22.

If the mixture contains five molecules of each component, then the total number of atoms can be found as shown below,

  $\begin{array}{l}Totalnumberofatoms=5*22\\ =110\end{array}$

Therefore, there are 110 atoms present in the mixture that contains five molecules of each component.

(d)

Interpretation Introduction

Interpretation:

The total number of hydrogen atoms that is present in the mixture that contains four molecules of each component has to be given.

Concept Introduction:

The composition of a chemical compound can be presented in a very precise was with the use of chemical formula.  Chemical formula uses chemical symbols of the elements that is present in the compound and numerical subscripts that represent how many number of atoms of each element is present in the compound.

Answer to Problem 1.87EP

There are a total of 56 hydrogen atoms present.

Explanation of Solution

Given molecules in mixture are $N_2,N_2{H}_4,N{H}_3,C{H}_4,andC{H}_{3}Cl$.

Number of atoms in $N_2$:  As this molecule has a subscript “2”, the total number of atoms in $N_2$ is two.

Number of atoms in $N_2{H}_4$:  The total number of atoms is present in molecule is by summing up the subscript.  Two nitrogen atoms and four hydrogen atoms are present in it.  The total number of atoms in $N_2{H}_4$ is 6 atoms.

Number of atoms in $N{H}_3$:  The total number of atoms is present in molecule is by summing up the subscript.  One nitrogen atom and three hydrogen atoms are present in it.  The total number of atoms in $N{H}_3$ is 4 atoms.

Number of atoms in $C{H}_4$:  The total number of atoms is present in molecule is by summing up the subscript.  One carbon atom and four hydrogen atoms are present in it.  The total number of atoms in $C{H}_4$ is 5 atoms.

Number of atoms in $C{H}_{3}Cl$:  The total number of atoms is present in molecule is by summing up the subscript.  One carbon atom, three hydrogen atoms and one chlorine atom is present in it.  The total number of atoms in $C{H}_{3}Cl$ is 5 atoms.

The total number of hydrogen atoms that is present in mixture which contains one molecule of each component can be found by summing up the number of hydrogen atoms in all molecules.  This gives the total number of hydrogen atoms as 14.

If the mixture contains four molecules of each component, then the total number of hydrogen atoms can be found as shown below,

  $\begin{array}{l}Totalnumberofhydrogenatoms=4*14\\ =56\end{array}$

Therefore, there are 56 hydrogen atoms present in the mixture that contains four molecules of each component.