Carbon and Fossil Fuels

Anthracite is the highest grade of coal, with the highest carbon content (86-97%) and the fewest impurities. It has the highest energy density among all coal types and burns with a clean, blue flame. The ranking of coals from lowest to highest quality is: lignite, sub-bituminous, bituminous, and anthracite at the top.

Butanol can be made from algae or diatoms using only a solar-powered biorefinery. This fuel has an energy density 10% less than gasoline, and greater than that of either ethanol or methanol. In most gasoline engines, butanol can be used in place of gasoline with no modifications.

When Poly Vinyl Chloride (PVC) is burnt, it produces dioxins (specifically, polychlorinated dibenzo-p-dioxins). Dioxins are highly toxic and persistent environmental pollutants that can cause serious health problems including cancer, reproductive issues, and immune system damage.

This is the correct option as this is not a use of natural gas. It is not used as a fuel to move turbines in hydropower plants.

Carbon black is added to rubber tyres as a reinforcing filler. It improves tyre strength, durability, and resistance to wear and UV damage. Graphite and charcoal are not used in tyre manufacturing, while coke is a fuel material.

Spark plugs are used in petrol (gasoline) engines to ignite the air-fuel mixture. Diesel engines use compression ignition, where fuel ignites solely from the heat of compressed air, requiring no spark plugs. The 'Both' option is incorrect because diesel engines fundamentally do not use spark ignition systems.

Something like oil can be good 'for' persons.

Wood has the lowest calorific value among these fuels due to high moisture content and lower carbon density compared to coal, charcoal, and processed fuels like kerosene. The calorific values rank approximately: kerosene > charcoal > coal > wood.

Example for alkane is ethane.

Methane family is also known as petroleum.

This is incorrect as coal is of four types, viz. peat, lignite, bituminous and anthracite. Lignite is a low grade brown coal, which is soft with high moisture content.

This is the correct option. Petrol cannot be used to control air pollution.

Petroleum refining produces multiple useful products through fractional distillation. Kerosene is used as fuel and in lighting. Diesel powers engines. Paraffin wax is used in candles and packaging. Since all three are obtained from petroleum, 'All of these' is the correct answer.

Combustion (burning) requires three things: fuel, heat, and oxygen. This is called the fire triangle. Petrol and kerosene are fuels, not the requirement for burning itself. Nitrogen does not support combustion (it's used in fire extinguishers). Oxygen is the essential reactant that enables burning.

Coal is formed from ancient plant matter that was compressed and heated over millions of years, giving it an organic origin. Sand is inorganic (silica). Sodium is a chemical element. Nylon is a synthetic polymer made from petrochemicals, so while carbon-based, it's not naturally organic in origin like coal.