Chapter U4.77, Problem 3E

Interpretation Introduction

Interpretation:

The given table should be completed.

Concept Introduction:

The amount of the substance that contains same number of the atoms or the particles or the molecules is known as mole. The mass of the atoms that are present in the chemical formula is termed as Molar mass. It corresponds to the sum of the atomic masses of all atoms that are present in the formula of the any compound.

Answer to Problem 3E

The complete table is represented as follows:

Chemical formula	Molar mass (g/mol)	Moles of what?
Ne(s)	20.180	1 mol Ne atoms
Ca(s)	40.078	1 mol Ca atoms
CO2(g)	44.009	1 mol carbon dioxide molecules
CaCO3(s)	84.087	1 mol calcium carbonate units
CH4O(l)	32.042	1 mol methanol molecules
C2H6O(l)	46.069	1 mol ethanol molecules
Fe2O3(s)	159.687	1 mol iron oxide units

Explanation of Solution

Ne is an element having atomic number 10 and molar mass 20.180 g/mol.

Ca is an element of alkaline earth metals with atomic number 20 and molar mass 40.078 g/mol.

CO₂ is a compound made up of one carbon atom and two oxygen atoms thus, the molar mass of CO₂ is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{CO}}_{\text{2}}=1\times \text{C}+2\times \text{O}\\ =\left(1\times 12.011+2\times 15.999\right)\text{g/mol}\\ =44.009\text{g/mol}\end{array}$

CaCO₃ is a compound made up of one calcium, one carbon atom and three oxygen atoms thus, the molar mass of CaCO₃ is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{CaCO}}_{\text{3}}=1\times \text{Ca}+1\times \text{C}+3\times \text{O}\\ =\left(1\times 40.078+1\times 12.011+3\times 15.999\right)\text{g/mol}\\ =84.087\text{g/mol}\end{array}$

CH₄O is a compound made up of one carbon atom, 4 hydrogen atoms and one oxygen atoms thus, the molar mass of CH₄O is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{CH}}_4\text{O}=1\times \text{C}+4\times \text{H}+1\times \text{O}\\ =\left(1\times 12.011+4\times 1.008+1\times 15.999\right)\text{g/mol}\\ =32.042\text{g/mol}\end{array}$

C₂H₆O is a compound made up of two carbon atom, 6 hydrogen atoms and one oxygen atoms thus, the molar mass of C₂H₆O is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{C}}_2{\text{H}}_6\text{O}=2\times \text{C}+6\times \text{H}+1\times \text{O}\\ =\left(2\times 12.011+6\times 1.008+1\times 15.999\right)\text{g/mol}\\ =46.069\text{g/mol}\end{array}$

Fe₂O₃ is a compound made up of two iron atoms and 3 oxygen atoms thus, the molar mass of Fe₂O₃ is calculated as follows:

  $\begin{array}{c}\text{Molar}\text{mass}\text{of}{\text{Fe}}_2{\text{O}}_3=2\times \text{Fe}+3\times \text{O}\\ =\left(2\times 55.845+3\times 15.999\right)\text{g/mol}\\ =159.687\text{g/mol}\end{array}$