Entry 6

Hey :)

Today we had two parts to the lesson. The first part was a summary to the chapter on Elements, Compounds and Mixtures and we also started on a new chapter: Separation Techniques. The second part of the lesson was a Formative Assessment (FA) that allowed the teacher to gauge how much we understood from the first chapter Elements, Compounds and Mixtures.

Summary

Mixtures

• 2 or more substances added together and are not chemically joined together. 
• 2 elements 
• Mixture of 2 compounds 
• 1 element & 1 mixture. 

e.g H2O & CO2

      H2*NH2  (1 element, 1 compound) 

• Filtration, fistillation, chromatography 
• electricity/chemical reactions. 

Alloy

- Mixture of metals and other elements 

- Stronger 

e.g Bronze, stainless steel 

Steel

- Iron + Carbon 

Stainless steel 

- Iron, chromium, carbon

Brass

- Copper, Zinc

Bronze

-Copper, Tin

Separation Techniques

• Mixture 
• Physical Methods

Filtration

One substance soluble, one not soluble in water. 

Why PURE? 

• Health hazards
• Medicine: water, food etc. 
• Characteristics: properties, melting point, density 
• Identification: test to prove, separate first 
• Production of useful substances 
• No such things called 100% pure there can only be 99.99999% pure. 

Paper Chromatography

• Separate a mixture of solutes with different solubility & degree of absorption/ 
• More soluble->move further up
• Not so soluble-> stay below
• This method uses a solvent moving over a porous/absorbent medium (e.g paper/gel) to separate. 
• dye/sugar (glucose/fructose)

This is an example of what experiment i will be doing this friday in the lab session! Definitely eager to share my experience with you! As the solvent travels up the paper, the dye dissolves. Some dyes are less soluble, so they travel even faster upwards. 

Take note! 

1. Dont let the ink touch the solvent as it will soak up very quickly. 

Separation depends on....

• solubility of the dyes in the solvent. 

That will be all for the first part of the lesson! It was very interesting and enjoyable!! The next part was just our test about the first chapter. I felt the test was not that straightforward but doable :) Thank you for reading!! Hope that you will continue visiting my blog! 

HAHA!!