Chapter 10, Problem 188A

Interpretation Introduction

Interpretation:

Given samples needs to be ranked based on least number of atoms to greatest number of atoms.

Concept introduction:

One mole compounds contains Avogadro’s number (N_A) of molecules which is $\text{6}\text{.023}\times {\text{10}}^{\text{23}}\text{.}$

Answer to Problem 188A

Number of atoms follows the following order.

0.5 mol Ag₂S<1 mol H₂<0.75 mol H₂O<1.5 mol NaCl

Explanation of Solution

H₂, NaCl, Ag₂S and H₂O are diatomic, diatomic, triatomic and triatomic molecules respectively.

Molecules in 1 mol H₂=N_A.

Atoms in 1 mol H₂${\text{=2×N}}_{\text{A}}\text{.}$

Molecules in 1.5 moles NaCl $\text{=1}{\text{.5×N}}_{\text{A}}\text{.}$

Atoms in 1.5 moles NaCl $\text{=2}\times \text{1}{\text{.5×N}}_{\text{A}}\text{=3}\times {\text{N}}_{\text{A}}\text{.}$

Molecules in 0.5 mol Ag₂S $=0.5\times {\text{N}}_{\text{A}}\text{.}$

Atoms in 0.5 mol Ag₂S $\text{=3}\times 0.{\text{5×N}}_{\text{A}}\text{=1}\text{.5}\times {\text{N}}_{\text{A}}\text{.}$

Molecules in 0.75 mol H₂O $=0.75\times {\text{N}}_{\text{A}}\text{.}$

Atoms in 0.75 mol H₂O $\text{=3}\times 0.{\text{75×N}}_{\text{A}}\text{=2}\text{.25}\times {\text{N}}_{\text{A}}\text{.}$

Here, the value of $N_A$ is $6.022\times {10}^{23}$.

Thus, the NaCl will have maximum number of molecules and Ag2S has minimum number of molecules in the sample.

Conclusion

Samples are ranked as per least number of atoms to greatest number of atoms as follows:

0.5 mol Ag₂S<1 mol H₂<0.75 mol H₂O<1.5 mol NaCl