Question

When sulfur dioxide reacts with chlorine, the products are thionyl chloride, \(\mathrm{SOCl}_{2}\), and dichlorine monoxide, \(\mathrm{OCl}_{2}\) \(\mathrm{SO}_{2}(\mathrm{~g})+2 \mathrm{Cl}_{2}(\mathrm{~g}) \longrightarrow \mathrm{SOCl}_{2}(\mathrm{~g})+\mathrm{OCl}_{2}(\mathrm{~g})\) (a) In what period of the periodic table is \(\mathrm{S}\) located? (b) Give the complete electron configuration of \(S\). Do not use the noble-gas notation. (c) \(\Lambda n\) atom of which element involved in this reaction (O. S, or C.1) should have the smallest first ionization energy? The smallest radius? (d) You want to make 675 g \(\mathrm{SOCl}_{2}\). Calculate what mass, in grams, of \(\mathrm{Cl}_{2}\) is required. (e) If you use \(10.0 \mathrm{~g} \mathrm{SO}_{2}\) and \(20.0 \mathrm{~g} \mathrm{Cl}_{2}\), determine the theoretical yield of \(\mathrm{SOCl}_{2}\)

Short answer

(a) Period 3; (b) 1s² 2s² 2p⁶ 3s² 3p⁴; (c) S, Cl; (d) 804.07 g Cl₂; (e) 18.56 g SOCl₂.

Step-by-step solution

Locate S in the Periodic Table

Sulfur (S) is located in Period 3 of the periodic table. Periods refer to the horizontal rows in the table.

Electron Configuration of Sulfur

Sulfur has an atomic number of 16. The complete electron configuration is: \( 1s^2 2s^2 2p^6 3s^2 3p^4 \). This distribution reflects the filling of the electron orbitals according to the Aufbau principle.

Determine Element with Smallest First Ionization Energy and Radius

Among O, S, and Cl, sulfur (S) has the smallest ionization energy due to its larger atomic size compared to oxygen. Chlorine (Cl) has the smallest atomic radius due to its effective nuclear charge being greater than that of sulfur and oxygen.

Calculate Mass of Cl2 for 675g of SOCl2

The reaction can be balanced as:\[ \mathrm{SO}_2 + 2 \mathrm{Cl}_2 \rightarrow \mathrm{SOCl}_2 + \mathrm{OCl}_2\] and the molar masses are: \(\mathrm{SOCl}_2 = 118.97\,\mathrm{g/mol},\ \mathrm{Cl}_2 = 70.90\,\mathrm{g/mol} \). Convert 675g \(\mathrm{SOCl}_2\) to moles: \(\frac{675}{118.97} \approx 5.67\,\mathrm{mol}\). According to the stoichiometry, 2 moles of \(\mathrm{Cl}_2\) are required per mole of \(\mathrm{SOCl}_2\), so you need \(5.67 \times 2 = 11.34\,\mathrm{mol}\) of \(\mathrm{Cl}_2\). Convert moles of \(\mathrm{Cl}_2\) to grams: \(11.34 \times 70.90 = 804.07\,\mathrm{g}\).

Theoretical Yield of SOCl2 from Given SO2 and Cl2

Determine moles of reactants: \(\mathrm{SO}_2\), \(\frac{10.0}{64.07} = 0.156\,\mathrm{mol}\); \(\mathrm{Cl}_2\), \(\frac{20.0}{70.90} = 0.282\,\mathrm{mol}\). The reaction requires twice as much \(\mathrm{Cl}_2\) as \(\mathrm{SO}_2\), so \(0.156\,\mathrm{mol}\) \(\mathrm{SO}_2\) needs \(0.312\,\mathrm{mol}\) \(\mathrm{Cl}_2\), making \(\mathrm{SO}_2\) the limiting reactant since only \(0.282\,\mathrm{mol}\) \(\mathrm{Cl}_2\) is available. \(0.156\,\mathrm{mol}\) of \(\mathrm{SO}_2\) produces \(0.156\,\mathrm{mol}\) of \(\mathrm{SOCl}_2\). Convert \(\mathrm{SOCl}_2\) moles to grams: \(0.156 \times 118.97 = 18.56\,\mathrm{g}\).

Key concepts

Periodic Table Period

The periodic table is divided into horizontal rows called periods. Each period corresponds to the number of electron shells an atom possesses. Sulfur (S) is found in Period 3. This means that sulfur has three electron shells around its nucleus. The further you move down the periodic table, from period to period, the larger the atoms become because they have more electron shells.

Understanding which period an element is in helps with predicting its properties and behavior in chemical reactions. For instance, elements in the same period share having an equal number of occupied electron shells, but different chemical properties, as the electrons are added to different orbitals.

Electron Configuration

Electron configuration describes the arrangement of electrons around the nucleus of an atom. This configuration is crucial in understanding chemical properties and reactivity. Sulfur, with an atomic number of 16, has its electrons configured as follows: 1s² 2s² 2p⁶ 3s² 3p⁴.

The notation reflects the filling of electrons in atomic orbitals based on the Aufbau principle. This principle states that electrons occupy the lowest energy orbitals first. The configuration indicates that sulfur's outer shell has six electrons, which impacts its chemical behavior. These outer electrons are known as valence electrons, and they determine how the atom interacts with other atoms.

Ionization Energy

Ionization energy refers to the energy needed to remove an electron from an atom. This energy depends on factors like atomic size and effective nuclear charge. In a group, as you move down the periodic table, ionization energy typically decreases due to an increase in atomic size. Electrons are farther from the nucleus and easier to remove.

In the third period, for example, among oxygen (O), sulfur (S), and chlorine (Cl), sulfur has the smallest first ionization energy. Although chlorine has a smaller atomic radius than sulfur, giving it a higher ionization energy, the same does not hold between sulfur and oxygen, as sulfur's more considerable size from more electron shells results in lower ionization energy. This is why sulfur requires less energy than oxygen to remove its valence electron.

Stoichiometry

Stoichiometry is a concept that involves calculating the proportions of reactants and products in chemical reactions. It uses balanced chemical equations to determine relationships between substances. In the given reaction of sulfur dioxide with chlorine, stoichiometry tells us how much chlorine ( Cl₂) is required to produce a certain amount of products.

For example, to produce 675 grams of thionyl chloride ( SOCl₂), you first convert this mass to moles using the molar mass of SOCl₂ (118.97 g/mol). According to the reaction's stoichiometry, which states that it takes two moles of Cl₂ for every mole of SOCl₂ produced, you'd calculate that 11.34 moles of Cl₂ are needed. Then, converting from moles of Cl₂ to grams allows you to determine the necessary 804.07 grams of chlorine needed to achieve this yield. This meticulous process is essential for practical chemistry applications, ensuring efficient and cost-effective reactions.