Trends in Chemistry (Period 3, Group I, II, IV, VII)

The Periodic Table is like a map, in which we read in the same way we'd read an English novel. From the lay out of the Periodic Table itself... we can extract a lot of information, first and foremost the electronic configuration of an element. From there, we can determine its properties, and even deduce probable reactions and compounds formed.

There are a trends that we look for:
1) Electronic Configuration
2) Atomic Radius
3) Ionic Radius
4) Melting & Boiling Point
5) Electrical Conductivity
6) Ionisation Energy
7) Electronegativity

Remember, in most cases for Inorganic Chemistry, look to the Periodic Table for guidance. Think about atomic/ionic charges, sizes ---> Charge density, electronegativity differences, redox, hydrolysis, decomposition, etc...

A topic that requires a great deal of reasoning ability.

Past Year Paper Afternoon Sessions

The Chemistry Department has kindly volunteered their time to go through PYPs with students @ LT 1 or 2 on Tuesday Afternoons from 2:30 - 4:30 pm every week. We might expand sessions to Wednesday Afternoons. Please take note that our tutors are sacrificing quite an amount of time just to help students score better in their exams. Reciprocation of this on the part of the students is REQUIRED. DO NOT COME TO THESE SESSIONS WITHOUT HAVING DONE THE PAPERS ALLOCATED PER WEEK! The sessions will be fast-paced; meant for students who have already tried the papers, and found questions that were too difficult / tricky to answer. If you are slow in the session due to your own lack of attempts, we cannot slow down for you. A team is only as fast as their slowest player. Nonetheless, we will be available to help you out with those really difficult questions that you could not understand even in the revision session during our Free Blocks. Do not hesitate to request for more help!

Past Year Paper Schedule 2010
6^th April, 2010: June P1 2003

13^th April, 2010: June P2 2006

20^th April, 2010: November P2 2009

27^th April, 2010: TBA but most probably a Workshop on Reaction Mechanisms
Going for June P2 2009; Reaction Mechanisms to be done in respective classes.

Electrochemistry Revision & Reading

There isn't much on chemguide about A2 Electrochemistry. You folks are going to have to depend quite heavily on my notes this time. There's some on AS Electrochemistry on Chemguide, which includes Electrolysis of Brine

Basic pointers regarding the drawing of the experimental setup:
1) SHE always on the left in diagram
2) Sign of electrode potential as measured from voltmeter = charge of RHS electrode
3) Labeling of direction of flow of electrons is done ONLY on the voltmeter wire

Basic pointers regarding the construction of a cell diagram:
1) (-) on the left; (+) on the right
2) | to denote a boundary between electrode & electrolyte
3) // to denote the salt bridge
4) Either side of a cell diagram will be the solid electrodes
5) Electrons are lost on the left, and gained on the right

N.B. DO NOT CONFUSE THE Cell Diagram with the experimental setup diagram.

If anyone has good links for Electrochemistry A2 please feel free to post!

Update: So far, in class, we've gone through the cell diagrams / experimental setup for measuring the electrode potentials for Zn²⁺/Zn, Cu²⁺/Cu & Cl₂/Cl^- half-cells.
The class will go home and research on the case for measuring the standard electrode potentials for Cr³⁺/Cr²⁺ & Fe³⁺/Fe²⁺ systems.

Update (14/4/2010): Pt(s)|Cr²⁺(aq),Cr³⁺(aq)//Fe³⁺(aq),Fe²⁺(aq)|Pt(s)
AND
Zn(s)|Zn²⁺(aq)//Cu²⁺(aq)|Pt(s)
DONE in class for those who were polite enough to be PRESENT.