Return of CCT Paper

Dear all,

I shall be returning the CCT Paper on Friday, 4th May 2007. It will be in LT3, 1345 hrs - 1445 hrs. We shall be going through the paper then.

For those who are not taking HMT, you could collect your paper from me in 4I classroom on Thursday, 5th May, at 1415 hrs (should end at 1515 hrs). Otherwise, you will have to collect it on Friday with the rest who are taking HMT.

Do inform me if you are unable to attend either sessions.

Long Weekend Assignment

Yoz,

Hope u have recovered from the CCT trauma. Anyway, what's done is done. We just have to realise the mistakes we have made and just ensure that we do not repeat them next time.

Now, as I've told u in class, please complete this piece of assignment over the weekends and hand it up the first lesson when we meet after the holidays.

Fuel Cell Assignment - Write a report answering the following questions:

1. What is a hydrogen fuel cell and how does it work?

2. What other fuel cells are available?

3. What are some applications of the fuel cells?

The report must be type written and of the length of about one A4 page. A minimum of 5 references must cited (of which at least two is printed resources). The penalty for not handing this up is the deduction of 5 MARKS from the CCT.

Happy working! =)

p.s. there will be a OBA on Fuel cell and electrochemical cell when we meet for the first lesson after the holidays.

Take a break, Have some negative ions to calm you.

Yoz,

Dun be too stressed mugging. Take a break.

I was searching for Rb that one of you is asking about when I chanced upon this.

There must be quite a lot of anions out there during our lessons rite?
















Picture taken from http://www.webelements.com/webelements/elements/text/Rb/key.html

Actually, have you ever come across some devices (e.g. aircon) that are said to be 'healthier' cos of some negative ions thingy? Here's an article which you might want to read: What's In A Breath of Fresh Air?

Ok, enough of rest, go back to your mugging.

=)

Build your own Blast Furnace

Yoz.

If you are stressed revising for the Chem CCT, try this activity to destress:

http://www.bbc.co.uk/history/british/victorians/launch_ani_blast_furnace.shtml

It tells you about the history behind iron extraction and reinforces your idea of the inputs and outputs of the blast furnace.



Picture taken from http://www.bbc.co.uk/

All about Steel

Dear all,

Hi. There seems to be some confusion created by the video taken was shown in class. In the video, pig iron snapped at a force of 6 tons, while steel snapped at a force of 8 tons. What do these show?

Actually, we are measuring tensile strength, i.e. the maximum load in tension a material will withstand before fracturing, or the ability of a material to resist being pulled apart by opposing forces. Hence, I would infer that this property is related to brittleness.

From our notes on alloys (Para 5), it was said that 'brittleness increase as the carbon content increases'. This is exactly what is shown in the example above.

To clarify the terms used on metal, here's quite a good resource:
http://www.arcraftplasma.com/metalchar.htm

Actually, if you are seriously interested in finding out more about strength of steel, you could read this article. Basically, it seems to suggest that strength of steel depends not only on carbon content, but also a variety of other factors.

http://www.key-to-steel.com/default.aspx?ID=CheckArticle&NM=11

To find out more about the other factors, here's a link:
http://www.matter.org.uk/steelmatter/metallurgy/6_1.html

Lastly, there is this interesting article that is highly related to our study on Metal extraction and steel making. In summary, MIT is suggesting to make steel through electrolysis. But why are we not doing it? What are the benefits and disadvantages?

http://web.mit.edu/newsoffice/1996/steelmaking.html


Steel wire. Taken from http://en.wikipedia.org/wiki/Steel

Summary of Reactions of Metals

Yoz,

Here's a summary I've gotten from Encarta.

Q1. In class, we have agreed that Hydrogen is placed above Cu since Cu is unable to displace it from the water, steam or acid. However, the observation reported by Encarta is different (see Pb). Why?

Q2. If Hydrogen were less reactive than Fe, why is it able to reduce Fe2O3? What conditions are required for the reduction to take place? What does this tells us about reactivity of Hydrogen? Would we then be able to use carbon to extract reactive metals from their ores?

Please give your comments.


Picture taken from:
http://encarta.msn.com/media_461542064/Reactivity_Series.html

Chem CCT Postponed

Dear all,

Please be informed that the Chemistry CCT would be postponed to 26 April (Thurs, Week 6).

Best of luck to those involved in the various SYF competitions!