• 1st used to separate pigments and dyes
• Procedure can be found in prac bk & science notes, so READ UP
• haha, here are some stuff to tke nte when writing out procedure for paper chrotography

- pencil line

- small drop of solute

- and other stuff that mr wong wrote onto the board... cant recall everything.... sry...

• 2 methods for paper chromatography
• a) Ascending method

-solvent ascends by capillary action

- rate of ascent slow, results in sharp defined spots

• b) Descending method

- faster as solvent is allowed to travel down by capillary action & gravitational force
- longer piece of paper often used, so that the spot have a longer distance to spread out

• Rf value

- basically the proportion of each chromatogram

- Rf value= distance travelled by solute divided by distance travelled by solvent front

- Note: Rf value cannot be more than 1.

How to check if somthing is pure

• boiling & melting point ( constant or narrow range of temp.)
• Chromatography ( sensitive and shows even very small amonuts of impurity)

Purity

• Imoportant
• must ensure that food & medicine do not contain harmful substance

Ok, im done for this topic... Lets continue with solutions and suspensions.....

Solutions and Suspensions

Solutions

• Mixture in which components are evenly mixed
• homogenous and uniform mixture of 2 or more substance
• Solute- substance that dissolves
• Solvent- substance that dissolves solute
• Aqueous solution- solution where water is solvent

Types of solutions

Imagine this is a table

State of solute State of solvent E.g.
Solid Solid Alloys (brass)
Solid Liquid 1. Salt solution 2. Amalgam
Liquid Liquid Alcoholic drinks
Gas Liquid Fizzy drinks
Gas Gas Air

Sorry hor, blogger no table one...

Strength of solution

• A dilute solution contains smaller amount of solute
• Concentrated solution is opp. opf dilute
• Saturated solution contains the max. amount of dissolved solute in a given volume at a particular temp.

Nature of solutions

• Solutions are formed when solute breaks down into tiny partiocles by solvent
• homogenous
• When a solution is filtered, no residue is left behind\

Suspensions

• Mixture where small solid or liquid particles are suspended in liquid or gas
• non-homogenous/ heterogenous
• E.g. chalk dust in water

Nature of solutions

• insoluble particles are big enough to prevent light passing through
• particles will settle to the bottom when left to stand for some time
• Usually cloudy

Solubility

• amount of solute that can dissolve in a given amount of solvent at a fixed temp.
• Factors that affect: nature of solvent, nature of solute, temp. of solvent

LOL, the notes are done... pt 2 is completed!!!!!!!! haha lol, as i said, these ntes are jus a "copy" of the science ntes... and it might nt be accurate, cos i wasnt really concentrating on what i wrote... so DONT rely on these ntes for ur chem exam... so JIAYOUS!!!!!!!!!!! :DDDDDDDD