Wild Chemistry Ride 6:


Simple Distillation

Distillation involves only two physical changes: 1. The liquid/ solution mixture is boiled to vaporise the most volatile component in the mixture; 2. The vapour is cooled by cold water in the condenser to condense it back to a liquid, which is the distillate, and is collected

Essentially, simple distillation is based on the principle of the lower boiling point of miscible liquids

Distillation can be used to purify water  and separate two miscible (=forming a homogeneous mixture when adde together ) liquids, like in a desalination plant and oil refineries.

Fractional Distillation

It separates a mixture of miscible liquids using a fractionating column and by the order of boiling points: the liquid with the lowest boiling point is distilled first, while the liquid with the highest boiling point is distilled last. Fractional distillation makes use of condensers as well, and the differences between fractional distillation and simple distillation are: 

• Fractional distillation uses a fractionating column while simple distillation does

• Fractional distillation consumes more energy than simple distillation

• Fractional distillation has much better separation between liquids than simple distillation

• Fractional distillation separates immiscible liquids with difference in boiling points of approximately 20-25 degrees Celsius

Wild Chemistry Ride 5:


Elements, Compounds and Mixtures

This was a topic which was quite confusing for some, but fortunately with prior reading I didn't find it that bad. So I've learnt that matter is classified into 3 categories: elements, compounds and mixtures. 

• Element: A substance made up entirely from only one type of atom
• Compound: A substance which is made up of two or more elements chemically combined in a fixed composition
• Mixture: A substance made-up of two or more elements or compounds not chemically combined in a fixed composition, and these components can be physically separated. 

There had been some confusion on identifying molecules, which are the smallest particles in an element or compound that has the properties of the element or compound, and they have to contain two or more atoms. And one misconception that some of us had was that a monatomic substance is a molecule, which we later learnt was untrue.

It was interesting how the atomic number was the proton number which is unique for every element, and that the number of protons is equal to the number of electrons. And as such we discovered that the number of neutrons is the proton number deducted from the mass number (which indicates the total number of protons and neutrons in an atom)