1. State and explain the state of hybridization of i) CO_(3)^2- ii) Graphite iii) BF_(4) 2. Group two elements and their oxides can form carbides by directly combining with carbon. Write an equation for the hydrolysis of Beryllium carbide and give one importance of this reaction 3. Discuss the following (3 Marks) i) The pattern of variation in the oxidation states of B to Tl (4 Marks) ii) Aluminum alloys are used to make aircraft body 4. Alkyl silicon chlorides are starting materials for formation of silicones. (6 Marks)

1. State and explain the state of hybridization of<br />i) $CO_{3}^{2-}$: The state of hybridization of $CO_{3}^{2-}$ is sp2. In this ion, the central carbon atom is bonded to three oxygen atoms, forming a planar trigonal planar geometry. The carbon atom uses three sp2 hybrid orbitals to form sigma bonds with the oxygen atoms, and one p orbital remains unhybridized, which forms a pi bond with one of the oxygen atoms.<br />ii) Graphite: The state of hybridization of graphite is sp2. In graphite, each carbon atom is bonded to three other carbon atoms, forming a planar hexagonal structure. The carbon atoms use three sp2 hybrid orbitals to form sigma bonds with their neighboring carbon atoms, and one p orbital remains unhybridized, which forms a pi bond with one of the neighboring carbon atoms.<br />iii) $BF_{4}$: The state of hybridization of $BF_{4}$ is sp3. In this molecule, the central boron atom is bonded to four fluorine atoms, forming a tetrahedral geometry. The boron atom uses four sp3 hybrid orbitals to form sigma bonds with the fluorine atoms.<br /><br />2. Group two elements and their oxides can form carbides by directly combining with carbon. Write an equation for the hydrolysis of Beryllium carbide and give one importance of this reaction.<br />The equation for the hydrolysis of Beryllium carbide is:<br />$Be_{2}C_{3} + 6H_{2}O \rightarrow 2Be(OH)_{2} + 3CH_{4}$<br />One importance of this reaction is that it provides a source of methane gas, which can be used as a fuel or as a raw material for the production of various chemicals.<br /><br />3. Discuss the following<br />(3 Marks)<br />i) The pattern of variation in the oxidation states of B to Tl: The oxidation state of an element refers to the number of electrons that an atom loses or gains when forming a compound. The pattern of variation in the oxidation states of B to Tl is as follows:<br />Boron (B) has an oxidation state of +3, Aluminum (Al) has an oxidation state of +3, Gallium (Ga) has an oxidation state of +3, Indium (In) has an oxidation state of +3, and Thallium (Tl) has an oxidation state of +1 or +3. This pattern is due to the increasing atomic size and the shielding effect of the inner electrons as we move down the group.<br /><br />ii) Aluminum alloys are used to make aircraft body: Aluminum alloys are used to make aircraft bodies because they have a low density, high strength, and good corrosion resistance. Aluminum alloys are lightweight, which reduces the overall weight of the aircraft and improves fuel efficiency. They also have high strength, which provides structural integrity and safety. Additionally, aluminum alloys are resistant to corrosion, which helps to prevent rust and maintain the appearance and longevity of the aircraft.<br /><br />4. Alkyl silicon chlorides are starting materials for formation of silicones. (6 Marks)<br />Alkyl silicon chlorides are compounds that contain a silicon atom bonded to a chlorine atom and an alkyl group. They are commonly used as starting materials for the formation of silicones, which are a type of polymer made up of repeating units of silicon-oxygen bonds. The process of forming silicones from alkyl silicon chlorides involves a series of reactions, including hydrolysis, condensation, and polymerization. During hydrolysis, the alkyl silicon chlorides react with water to form silanols, which are then condensed to form oligomers. Finally, the oligomers are polymerized to form a silicone polymer. Silicones are widely used in various industries, including electronics, automotive, and medical, due to their excellent electrical insulating properties, chemical stability, and biocompatibility.