Aerosol

Everyone uses aerosol! But what is aerosol? Color spray, mosquito insecticide or anything that is under pressure and released as a fine spray. How does aerosol work? Aerosol is made up of two components which are the product and propellant. What is propellant and what is its function? The propellant act as the 'engine', the driving force of the aerosol.

The propellant mainly exists as liquefied gas in the head space above the product. When the aerosol valve is opened, the propellant pushes the product out of the can. The amount of propellant remains the same in the head space. However the space increases, leading to a drop in pressure. Some of the common propellants used are liquefied petroleum gas (LPG), chloroflorocarbon (CFC), carbon dioxide, compressed air and nitrogen gas.

What is petrol made of?

Do you know that petrol is made of a mixture of hydrocarbons? It mainly consists of octane C8H18. Opppsss, your car is running out of fuel. You go to a petrol station. You wonder what RON 95 and RON 97 are? Which one do you use? Of course the cheaper one LAH! Actually RON refers to Research Octane Number. The higher the number, the more the concentration of octane in the fuel. However it is expensive and difficult to produce petrol with only iso-octane in it. So, petrol consists of iso-octane, other hydrocarbons and some additives. Before that, people were adding tetraethyl lead as anti-knocking agent to prevent the fuel from exploding. It is now banned due to its poisonous nature. You go for higher rating fuel (RON 97), you pay more. But it is better for your car.

Testing the Presence of C=C Double Bond

Okay, your teacher gave you two solutions. Solution A is pentane and solution B is pentene. How would you distinguish between the two? Prepare two test tubes. Add a few drops of bromine water to both of the tubes containing pentane and pentene, respectively. Observe! That solution that decolourizes is PENTENE. Alkene undergoes halogenation with bromine to produce dibromopentane. No reaction between pentane and bromine water, reddish-brown colour remains.

Alkane

Let's take a closer look at the alkane. Alkane does not have any functional group. They are saturated hydrocarbons. Have you ever wondered what it means by n-butane, n-pentane? n refers to normal or straight chain hydrocarbon. Why it does not apply to propane? This is because ... propane has no isomers. n- only for isomers, starting from butane. You have isobutane, isopentane, etc.

Functional Groups

The chemical properties of organic compounds are determined by their functional groups. How many functional groups are there? Check this diagram posted below. Alkene, alkyne, haloalkane, etc. Have fun guys!

Introduction

Hi guys. I am Liong. I created this blog for you to learn the chemistry (I am learning too). You can find fun articles, school STPM syllabus, exam tips and so on. Don't worry. You don't get charged for having this freebies. Let's play the chemistry!