Chemical Properties of Carbon - Combustion - Part 2 | Don't Memorise

TL;DR

Saturated hydrocarbons burn with a blue flame, while unsaturated hydrocarbons and incomplete combustion result in a yellow flame with soot.

Transcript

we ended the previous video with a question why does methane give us a blue flame without any soot and why does wood burned with a yellow flame with soot let us try finding out the answers there are two important perspectives here one is about what compound is undergoing combustion and the other is the way in which the burning process takes place l... Read More

Key Insights

• 💛 Whether a hydrocarbon burns with a blue or yellow flame depends on the presence of single or multiple bonds between carbon atoms.
• 😄 Saturated hydrocarbons burn with a blue flame due to the ease of breaking single carbon bonds.
• 💛 Unsaturated hydrocarbons require more effort to break double or triple carbon bonds, resulting in a yellow flame.
• 🥺 Incomplete combustion, caused by insufficient oxygen reaching the compound, leads to yellow flames and the production of soot.
• 💛 Wood burning rapidly can hinder oxygen access to deeper layers, causing incomplete combustion and a yellow flame with soot.
• 🫢 Clogged air holes in old gas burners prevent sufficient oxygen from reaching the fuel, resulting in yellow flames and soot production.

Questions & Answers

Q: Why does methane burn with a blue flame?

Methane is a saturated hydrocarbon, which means it has single covalent bonds between carbon atoms. The oxygen atoms can easily break these bonds, resulting in a blue flame.

Q: Why do unsaturated hydrocarbons burn with a yellow flame?

Unsaturated hydrocarbons have double or triple bonds between carbon atoms. Breaking these bonds requires more effort from oxygen atoms, leading to a yellow flame.

Q: Why does incomplete combustion result in a yellow flame with soot?

Incomplete combustion occurs when the oxidation process is not completed due to insufficient oxygen reaching the compound. This process produces a yellow flame with soot, as seen in burning wood and clogged gas burners.

Q: Why do old gas burners produce yellow flames and soot?

As gas burners get older, their air holes get clogged, leading to a lack of oxygen reaching the fuel. This incomplete combustion results in yellow flames and the production of thick black soot.

Summary & Key Takeaways

• Saturated hydrocarbons, which have only single covalent bonds between carbon atoms, burn with a clear blue flame.

• Unsaturated hydrocarbons, with double or triple bonds between carbon atoms, result in yellow flames due to the difficulty in breaking these bonds during combustion.

• Incomplete combustion, such as when wood burns rapidly, leads to a yellow flame with soot due to insufficient oxygen reaching the deeper layers.