Chapter U4.77, Problem 6E

(a)

Interpretation Introduction

Interpretation:

The mass of carbon atom in grams in one mole of methane should be calculated.

Concept introduction:

Mole is an SI unit that is used to measure the quantity of the substance. It is the quantity of a substance that contains the same number of atoms as accurately present in 12.00 g of carbon-12 is known as mole.

The number of moles is defined as the ratio of mass to the molar mass.

$\text{Number of moles = }\frac{\text{Mass (g)}}{\text{Molar mass}}$

The ratio of the mass of the given compound to the number of moles of the compound is known as molar mass.

The one mole of any substance is equal to the Avogadro number, i.e., $6.022\times {10}^{23}$ atoms.

Answer to Problem 6E

Mass of carbon atom in one mole of methane = 12 g.

Explanation of Solution

The given molecule is methane ( ${\text{CH}}_{\text{4}}$ ).

Number of moles of methane = 1 mole

In one mole of methane, one mole of carbon is present.

Molar mass of carbon = 12 g/mole.

Thus, the mass of carbon atom is one mole of methane = $\text{1 mole}\times \text{12 g/mole}$

Mass of carbon atom in one mole of methane = 12 g.

(b)

Interpretation Introduction

Interpretation:

The mass of carbon atoms in grams in one mole of methanol should be calculated.

Concept introduction:

Mole is an SI unit that is used to measure the quantity of the substance. It is the quantity of a substance that contains the same number of atoms as accurately present in 12.00 g of carbon-12 is known as mole.

The number of moles is defined as the ratio of mass to the molar mass.

$\text{Number of moles = }\frac{\text{Mass (g)}}{\text{Molar mass}}$

The ratio of the mass of the given compound to the number of moles of a compound is known as molar mass.

The one mole of any substance is equal to the Avogadro number, i.e., $6.022\times {10}^{23}$ atoms.

Answer to Problem 6E

12 g.

Explanation of Solution

The given molecule is methanol ( ${\text{CH}}_{\text{4}}\text{O}$ ).

Number of moles of methanol = 1 mole

In one mole of methanol, one mole of carbon is present.

The molar mass of carbon atom is 12 g/mol that is 1 mol of C atom has 12 g.

Therefore, the mass of carbon atom in 1 mol of methanol will be 12 g.

(c)

Interpretation Introduction

Interpretation:

The mass of carbon atoms in grams in one mole of ethanol should be calculated.

Concept introduction:

Mole is an SI unit that is used to measure the quantity of the substance. It is the quantity of a substance that contains the same number of atoms as accurately present in 12.00 g of carbon-12 is known as mole.

Number of moles is defined as the ratio of mass to the molar mass.

$\text{Number of moles = }\frac{\text{Mass (g)}}{\text{Molar mass}}$

The ratio of the mass of the given compound to the number of moles of the compound is known as molar mass.

The one mole of any substance is equal to the Avogadro number, i.e., $6.022\times {10}^{23}$ atoms.

Answer to Problem 6E

Mass of carbon atom in one mole of ethanol = 24 g.

Explanation of Solution

The given molecule is ethanol ( ${\text{C}}_2{\text{H}}_6\text{O}$ ).

Number of moles of ethanol = 1 mole

In one mole of ethanol, 2 moles of carbon are present.

The mass of 1 mol of carbon atom is 12 g thus, mass of 2 mol will be:

$m=2\times 12=24\text{ g}$