Sulfuric acid Lewis structure

C21-0031. The reaction between SO3 and H2 O to form sulfuric acid (H2 SO4) can be described in two steps formation of a Lewis acid-base adduct followed by Brcjmsted proton transfer. Draw Lewis structures illustrating these two steps, showing electron and proton movement by curved arrows. 

Figure 1.18 Lewis structures of oxo acids and oxides of phosphorus and sulfur (a) octet rule structures according to Lewis and (b) hypervalent structures.

The ready decomposition of most aryl azides with sulfuric acid and Lewis acids may be vigorous or violent, depending on structure and conditions. In absence of a diluent (carbon disulfide), phenyl azide and aluminium choride exploded violently. 

In the reaction of sulfur dioxide with water, S02 functions as a Lewis acid. Write the balanced chemical equation for the reaction, using Lewis structures. 

Just as mild oxidation converts thiols to disulfides, vigorous oxidation converts them to sulfonic acids. KMn04 or nitric acid (HN03), or even bleach (NaOCl), can be used as the oxidant for this reaction. Any Lewis structure of a sulfonic acid requires either separation of formal charges or more than 8 electrons around sulfur. Sulfur can have an expanded octet, as it does in SF4 (10 electrons) and SF6 (12 electrons). The three resonance forms shown here are most commonly used. Organic chemists tend to use the form with an expanded octet, and inorganic chemists tend to use the forms with charge separation. 

Sulfur trioxide (SO3) is an industrially important compound key to the production of sulfuric acid. It tends to polymeric forms both in the solid and liquid states. As a gas, the molecules have a planar triangular structure in which the sulfur atom has a high affinity for electrons. This explains its action as a strong Lewis acid towards bases that it does not oxidize. It can thus crystallize complexes with pyridine or trimethy-lamine. It has a very strong affinity for water and hence rapidly associates with water in the environment. 

Another molecule that has resonance structures is sulfur dioxide, SO2, shown in Figure 13. Sulfur dioxide released into the atmosphere is partly responsible for acid precipitation. The actual structure of SO2 is an average, or a resonance hybrid, of the two structures. Although you draw the structures as if the bonds change places again and again, the bonds do not in fact move back and forth. The actual bonding is a mixture of the two extremes represented by each of the Lewis structures. 

Example Major Lewis structures for sulfuric acid, H2S04(32 valence electrons)... 

Draw the Lewis structure of sulfuric acid (H2SO4). 

Write the Lewis structure for each of the following species, and indicate the structure of each (a) Se03 (b) S2CI2 (c) chlorosulfonic acid, HSO3CI (chlorine is bonded to sulfur). 

Alkenes are also sources of carbonium ions for alkylations. Protic acids— especially sulfuric acid, phosphoric acid, and hydrogen fluoride—and Lewis acids, such as BF3 and AIQ3, are used as catalysts. " Insofar as comparisons have been made, such factors as position selectivity and tendency toward isomerism of the alkyl group to more stable structures are similar to those described with alkyl halides as alkylating agents. ... 

In Chapter 15 we shall learn how the nitronium ion, N02, forms when concentrated nitric and sulfuric acids are mixed, (a) Write a Lewis structure for the nitronium ion. (b) What geometry does VSEPR theory predict for the N02 ion (c) Give a species that has the... 

Sulfuric acid (H2SO4), the most un)ortant industrial chemical in the world, is prepared by oxidizing sulfur to sulfur dioxide and then to sulfur trioxide. Although sulfur trioxide reacts with water to form sulfuric acid, it forms a mist of fine droplets of H2SO4 with water vapor that is hard to condense. Instead, sulfur trioxide is first dissolved in 98 pa-cent sulfuric acid to form oleum (H2S2O7). On treatment with water, concentrated sulfuric acid can be generated. Write equations for all the steps and draw Lewis structures of oleum based on the discussion in Example 9.11. 

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