#7 Entry- Summary of ECM, Separation Techniques

Today, we briefly summarised ECM and started a little on Separation Techniques.

Summary

Mixture of elements:

Which diagram shows the mixture of elements?

Ans: Z

Types of mixtures: 

• 2 elements
• 2 compounds
• 1 element, 1 compound

Compound must have fixed proportion of certain elements. A different proportion will result in a completely different compound. Eg H2O

Alloy:

• Mixtures of metals and other elements
• Stronger than normal metals (pure metals are malleable)
• eg bronze, stainless steel

Separation Techniques

Separation techniques are used to separate mixtures.

Types of techniques:

Filtration, distillation, chromatography and/or electricity, chemical reactions

Filtration: Used when one substance is soluble and the other is not soluble in water

Examples of Pure and Not Pure

Pure	Not Pure
Oxygen	Carbon Dioxide
Acid	Water

*pure: all elements on the Periodic Table

Why must substances be pure?

• Health hazards
• Food, medicine must be pure 
• Test out characteristics of certain elements: Properties such as melting point, boiling point, density
• Identification: Test to prove something, hence, have to separate first
• Production of useful substances
• There isn't 100% pure substances, at most, it can be 99.99999...% pure
• To determine the degree of purity: Mass Difference

How to determine if something is pure:

• Fix melting point, boiling point
• Chromatography: Separated into different components

Paper Chromatography:

• Separate mixtures of solutes with different solubility and degree of absorption
• More soluble: move further up
• Not so soluble: Stay at the same position
• Use a solvent medium/ porous or absorbent: paper/gel
• Dye/ Sugar (Sugar: Glucose/Fructose)

Process:

That's all for today!