Why are alkanes used as fuels?

Depending on the number of carbons, the calorific value of alkanes changes which is used as fuel. Because there is a large amount of heat released during the combustion of alkanes. Hence, the correct answer is option A. Note: Highly combustible and used as fuels are the alkanes.

Are alkanes used as fuels?

The alkanes are highly combustible and are valuable as clean fuels, burning to form water and carbon dioxide. Methane, ethane, propane and butane are gases and used directly as fuels. Alkanes from pentane up to around C17H36 are liquids.

Why are alkenes used as fuels?

Alkenes are not used as fuels because: They are scarce in nature. They are made from other hydrocarbons to make plastics, anti–freeze and many other useful compounds. They burn with a smoky flame due to less efficient, and more polluting incomplete combustion, so the heat energy release is lower than for alkanes.

Why are alkanes used more as fuels than alkenes?

The general formula for alkenes is CnH2n Alkenes are more reactive than alkanes. They react with bromine water and make it go from orange to colourless. Alkanes do not have a double bond so the bromine water stays orange. Smaller hydrocarbons make better fuels as they are easier to ignite.

Why are alkanes such as methane and butane used as fuels?

Alkanes are used as fuels because : ⇒ They are easily combustible . ⇒ The reactions are highly exothermic releasing a lot of energy. Hence they are excellent fuels.

Can alkenes be used as fuels?

Alkenes readily burn, just like alkanes, to give carbon dioxide and water if combustion is complete e.g. However, they are NOT used as fuels for two reasons. They are far too valuable for use to make plastics, anti–freeze and numerous other useful compounds.

Why are short chain alkanes serve as good fuels?

Short chain alkanes burn completely in a good supply of oxygen to give carbon dioxide and water. O(l)ΔH = -890 kJ mol-1 These combustion reactions give out large amounts of heat and have a very high negative enthalpy value, making them incredibly important to us as fuels.

Why do alkanes have a higher heat of combustion than alcohols?

In alkanes, the only intermolecular forces are van der Waals dispersion forces. Hydrogen bonds are much stronger than these; therefore, more energy is required to separate alcohol molecules than to separate alkane molecules. This is the main reason for higher boiling points in alcohols.

Why are alkanes better fuels than alkenes?

Why short chain alkanes serve as good fuels?

Why alkanes are better fuels than alkenes?

What are the main uses of alkanes?

Common usage of alkanes in natural gas

• heating/cooling house (air conditioning)
• ovens.
• fireplaces.
• outdoor lights.
• Fuel cells.
• plastic products (from cracking of ethane, propane)
• fertilizer (in Haber-Bosch process for production of ammonia, hydrogen comes from methane)
• fabric.

Why are alkanes important fossil fuels?

Alkanes are our most important fossil fuels. The combustion (burning) of alkanes (also known as oxidation) is highly exothermic. In a combustion reaction a substance reacts with an oxidising agent (e.g. oxygen), and heat and light are released.

What is released during the complete combustion reaction of alkanes?

In the complete combustion reaction of alkanes, carbon dioxide ( CO2 CO 2) and water ( H2O H 2 O) are released along with energy. Fossil fuels are burnt for the energy they release. The general reaction for the combustion of an alkane as a fossil fuel is given in the figure below.

Why do alkanes have a high boiling point?

The more carbon atoms in the chain, the greater the intermolecular forces and therefore the higher the boiling point. That means that these molecules will condense at higher temperatures. Alkanes are our most important fossil fuels. The combustion (burning) of alkanes (also known as oxidation) is highly exothermic.

What are some examples of cracking hydrocarbons?

Through this process long, bulky alkanes are broken up into smaller compounds. These compounds include shorter alkanes and alkenes. A few examples of cracking hydrocarbons are given in the figure below. The cracking of various hydrocarbons to produce alkanes and alkenes. There are two types of hydrocarbon cracking.