Correct option is B
The correct answer is (b).
Fossil fuels, predominantly petroleum, natural gas, and coal, are fundamentally defined chemically as complex hydrocarbons.
This inherently dictates that massive chains and rings of hydrogen atoms must be chemically bonded to the primary carbon backbone, forming the explosive energy-yielding molecules we ignite.
Information Booster
- The exact chemical ratio of hydrogen to carbon fundamentally determines the specific physical state and energy density of the fossil fuel.
- Methane (CH4), the primary constituent of natural gas, exhibits the absolutely highest hydrogen-to-carbon ratio, rendering it the cleanest-burning fossil fuel.
- During high-temperature combustion, these vital carbon-hydrogen bonds are violently broken, releasing massive heat energy alongside the byproducts of carbon dioxide and water vapor.
- Coal possesses an exceedingly low hydrogen-to-carbon ratio, explaining precisely why it acts as a dense solid and releases maximum carbon dioxide per energy unit.
- The deep geological process of fossil fuel formation involves the slow thermal cracking of organic macromolecules into smaller, energy-rich hydrocarbon chains.
- Fractional distillation at massive refineries systematically separates crude oil strictly based on the varying lengths of these hydrocarbon chains.
- The presence of hydrogen is so biologically fundamental that "hydrocarbon" is synonymous with conventional petroleum resources.
- Option A: Nitrogen is merely an impurity present in highly variable trace amounts within organic deposits; it unfortunately generates toxic NOx gases upon combustion, contributing heavily to acid rain.
- Option C: Sulphur is a severely polluting, variable contaminant highly prevalent in low-grade coal and "sour" crude oil, responsible for massive SO2 emissions and subsequent environmental acidification.
- Option D: Oxygen is completely expelled during the intense anaerobic diagenesis that forms fossil fuels; refined hydrocarbons are strictly heavily reduced, not oxidized, states of carbon.
- Understanding the precise hydrocarbon chemistry is vital for calculating exact stoichiometric combustion and regulating industrial emission controls.
English
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