Question

A compound composed of only carbon and chlorine is 85.5% chlorine by mass. propose a lewis structure for the lightest of the possible compounds that allows each atom to have a complete octet without formal charges. draw the molecule by placing atoms on the grid and connecting them with bonds. include all lone pairs of electrons.

Answer 1

$\boxed{{\text{CC}}{{\text{l}}_{\text{2}}}}$ is the lightest possible compound formed in the given case. Its structure is attached in the image.

Further explanation:

Lewis structure:

The bonding between the different atoms in covalent molecules is shown by some diagrams known as the Lewis structures. These also show the presence of lone pairs in the molecule. These are also known as Lewis dot diagrams, electron dot diagrams, Lewis dot structures or Lewis dot formula. In covalent compounds, the geometry, polarity, and reactivity are predicted by these structures.

Formal charge:

It is the charge that an atom acquires in a molecule by considering that the chemical bonds are shared equally between the two atoms, irrespective of their electronegativities.

Consider the mass of the compound to be 100 g.

Amount of chlorine in the compound is 85.5 %. So its mass can be calculated as follows:

${\text{Mass of chlorine}}=\left({\frac{{{\text{\% of chlorine}}}}{{{\text{100 \% }}}}}\right)\left({{\text{Mass of compound}}}\right)$                 …………….(1)

Substitute 85.5 % for the percentage of chlorine and 100 g for the mass of the compound in equation (1).

$\align{{\text{Mass of chlorine}}&=\left({\frac{{{\text{85}}{\text{.5 \% }}}}{{{\text{100\%}}}}}\right)\left({{\text{100g}}}\right)\cr&=85.5\;{\text{g}}\cr}$

As the compound contains only carbon and chlorine. The total mass of the compound is calculated by using the following expression:

${\text{Mass of compound}}={\text{Mass of carbon}}+{\text{Mass of chlorine}}$                 …… (2)

Rearrange equation (2) to calculate the mass of carbon.

${\text{Mass of carbon}}={\text{Mass of compound}}-{\text{Mass of chlorine}}$                 …… (3)

Mass of chlorine is 85.5 g.

Mass of the compound is 100 g.

Substitute these values in equation (3).

$\begin{aligned}\text{Mass of Carbon}&=100\text{ g}-85.5\text{ g}\\&=14.5\text{ g}\end{aligned}$

The formula to calculate the moles of compound is,

${\text{Number of moles}} = \frac{{{\text{Given mass}}}}{{{\text{Molar mass}}}}$                    …… (4)

The given mass of chlorine is 85.5 g.

The molar mass of chlorine atom is 35.45 g/mol.

Substitute these values in equation (4) to calculate the moles of chlorine in the compound.

$\align{{\text{Moles of chlorine}}&=\left({{\text{85}}{\text{.5 g}}}\right)\left({\frac{{{\text{1 mol}}}}{{{\text{35}}{\text{.45g}}}}}\right)\cr&={\bf{2}}{\bf{.41}}\;{\bf{mol}}\cr}$

The given mass of carbon is 14.5 g.

The molar mass of carbon is 12 g/mol.

Substitute these values in equation (4) to calculate the moles of carbon in the compound.

$\align{{\text{Moles of carbon}}&=\left({{\text{14}}{\text{.5g}}}\right)\left({\frac{{{\text{1 mol}}}}{{{\text{12g}}}}}\right)\cr&=1.208\;{\text{mol}}\cr&\approx{\bf{1}}{\bf{.21 mol}}\cr}$                   …… (5)

The moles of chlorine are 2.41 mol.

The moles of carbon are 1.41 mol.

Substitute these values in equation (5).

$\align{{\text{Required ratio}}&=\frac{{{\text{2}}{\text{.41 mol}}}}{{{\text{1}}{\text{.21 mol}}}}\cr&=1.99:1\cr&\approx{\bf{2:1}}\cr}$

The ratio of chlorine to carbon is 2:1. So the formula of the given compound is ${\bf{CC}}{{\bf{l}}_{\bf{2}}}$

Carbon has four valence electrons and it forms two single bonds with two chlorine atoms. While each chlorine atom has seven valence electrons and forms single bond with carbon atom to complete its octet. (Refer to the structure in the attached image)

Learn more:

1. Carbon dioxide and water have the same geometry or not? brainly.com/question/2176581

2. Which molecule is not described by a single Lewis structure? brainly.com/question/6786947

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Chemical bonding and molecular structure.

Keywords: Lewis structure, chlorine, carbon, 85.5 %, 100 %, 85.5 g, 14.5 g, CCl2, 2:1, formal charge, bonds, lone pairs, possible compounds, given mass, molar mass, 100 g, 35.45 g/mol, 12 g/mol.

Answer 2

Answer is in picture below.

Use 100 grams of the compound:

ω(Cl) = 85.5% ÷ 100%.

ω(Cl) = 0.855; mass percentage of the chlorine in the compound.

m(Cl) = 0.855 · 100 g.

m(Cl) = 85.5 g; mass of chlorine.

m(C) = 100 g - 85.5 g.

m(C) = 14.5 g; mass of carbon.

n(Cl) = m(Cl) ÷ M(Cl).

n(Cl) = 85.5 g ÷ 35.45 g/mol.

n(Cl) = 2.41 mol; amount of chlorine.

n(C) = 14.5 g ÷ 12 g/mol.

n(C) = 1.21 mol; amount of carbon.

n(Cl) : n(C) = 2.41 mol : 1.21 mol = 2 : 1.

This compound is dichlorocarbene CCl₂.