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

How Batteries work?

Yoz everyone,

So, we have all learnt how to create a battery using a fruit.

Now, Energizer actually has quite an interesting website on the working of Alkaline battery. http://www.energizer.com/learning/howbatterieswork.asp

Please visit the website and discuss in the 'comments' section:
1. What is the cathode of the battery.
2. What is the anode of the battery.
3. What electrolyte is used in the battery.
4. What reactions takes place at each electrode? Give the half equations.
5. How does electrons flow?

In addition, quite a number of you asked how a rechargeable battery works. The same website has a short description of it. You might want to read it too.


The human electrolyte? Do you think we can act as electrolytes?
Picture taken from http://www.exploratorium.edu/snacks/hand_battery.html

Revision for CCT: Redox

Guys, here's a website that will help you revise your REDOX:

http://www.chemguide.co.uk/inorganic/redoxmenu.html

These are the things you must be able to do after going through the website:

- Define Redox in terms of electron transfer and changes in oxidation state.
- Identify O.S. of a particular ELEMENT in a substance, e.g. What is Cl's O.S. in HOCl?
- Identify a redox reaction, the reducing agent and oxidising agent.
- Write half equations.
- Combine half equations to get ionic equations.

A whole list of practice problems can be found in this website:

http://www.chemtutor.com/redox.htm#osp


A pictorial representation of REDOX. Taken from http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookEnzym.html