Question

‌Answer the following:
(i) Write the molecular formula of silica.
(ii) Write the partial structure of silicone.
(iii) Name catalyst used in the gasoline production.
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Answer 1

Hint:‌Silica is a compound formed by silicon with another element. It is an oxide of Silicon with two oxygen atoms. So we write the formula of Silicon with two oxygen atoms to get the formula of silica. Partial structure of silicon contains organic compounds and oxygen with silicon. Gasoline is a hydrocarbon and is a mixture of different alkenes, alkanes, aromatics and cycloalkanes. So we have to find the catalyst which breaks up the hydrocarbon molecules to produce smaller hydrocarbons to form gasoline.
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Complete‌ ‌answer:‌(i) We know that Silica is an oxide of the silicon element. As the valency of silicon is 4 it can form two silicon-oxygen double bonds through covalent bonding. Silica is found in stones, soil and sand. Quartz is the most common form of Silica. And its molecular formula is $Si{O_2}$
(ii) Silicones are derived from silicon elements, organic compounds and oxygen atoms. As we know that the valency of silicon is 4, it can share 4 bonds. In silicones, each silicon atom is bonded with 2 organic groups (R) and 2 oxygen atoms. Every two consecutive silicon atoms are bonded by an oxygen atom between them.
The structure of Silicone is $ - O - \mathop {\mathop {\mathop {\mathop {Si}\limits^| }\limits^R }\limits_| }\limits_R - O - \mathop {\mathop {\mathop {\mathop {Si}\limits^| }\limits^R }\limits_| }\limits_R - O - $. Silicone is a silicon polymer. General formula of silicones is ${\left( {{R_2}SiO} \right)_x}$ where x can be any natural number.
(iii) Gasoline is a mixture of saturated and unsaturated hydrocarbons along with aromatic compounds like benzene. Gasoline production is a reforming process. For these reforming processes platinum is used as a catalyst as they help in breaking hydrocarbons into smaller hydrocarbons.
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Note: ‌Silica is not the same as silicon is not the same as silicone. Be careful with the spellings, names and their formulas. Silicon is an elastomer same as rubber but differs in their formulas, structures and features. Silicon is natural whereas silicone is synthetic.
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