AS chemistry

I am about to study a level chemistry and wanted to know the difficulties that you faced when studying redox reactions at AS. So that I ensure I work in those particular areas. Thank you.

Reply 1

Scienceisgood

Original post by sim.somal

I am about to study a level chemistry and wanted to know the difficulties that you faced when studying redox reactions at AS. So that I ensure I work in those particular areas. Thank you.

What don't you get about redox reactions?
Perhaps I can help?

Reply 2

HappyHylian

Redox Reactions aren't difficult. :O

Reply 3

sim.somal

Like I don't understand how to balance half equations and the h+ and h20

Reply 4

HappyHylian

Original post by sim.somal

Like I don't understand how to balance half equations and the h+ and h20

LOL. Quit now.

Reply 5

LECTERN LOBBY

Original post by sim.somal

I am about to study a level chemistry and wanted to know the difficulties that you faced when studying redox reactions at AS. So that I ensure I work in those particular areas. Thank you.

Hi there, post me an example question and I will try my best to take you through it. There is a useful acronym that we use in chem to describe oxidation and reduction in terms of whether a substance has gained or lost electrons.
OIL RIG
OIL means Oxidation- Is-Loss
RIG means Reduction - Is - Gain
But give me an e.g where your stuck and ill try to help you ok.
You can also follow me on twitter if your on there @lecternlobby

Reply 6

LECTERN LOBBY

Original post by sim.somal

I am about to study a level chemistry and wanted to know the difficulties that you faced when studying redox reactions at AS. So that I ensure I work in those particular areas. Thank you.

Reply 7

LECTERN LOBBY

Original post by sim.somal

I am about to study a level chemistry and wanted to know the difficulties that you faced when studying redox reactions at AS. So that I ensure I work in those particular areas. Thank you.

Hi there, post me an example question and I will try my best to take you through it. There is a useful acronym that we use in chem to describe oxidation and reduction in terms of whether a substance has gained or lost electrons. 
OIL RIG 
OIL means Oxidation- Is-Loss 
RIG means Reduction - Is - Gain 
But give me an e.g where your stuck and ill try to help you ok. 
You can also follow me on twitter if your on there @lecternlobby

Reply 8

mayamiller

Although I do not know which exam board you will be joining, I can assure you that CIE's latest book is head and shoulders above all other chem textbooks I have ever read. It has worked examples that you can comfortably follow and a CD ROM to help with the check up qstn. I wont lie, it's all a bit hard at first but after the 3rd try of revising you get the hang of it.
Here is a link
http://education.cambridge.org/af/subject/science/chemistry/cambridge-international-as-and-a-level-chemistry/cambridge-international-as-and-a-level-chemistry-coursebook-with-cd-rom
Good luck and tell me how it goes.

Reply 9

propagation

Original post by sim.somal

Like I don't understand how to balance half equations and the h+ and h20

Hi,

Take the following half equation:
MnO4^-1 ----> Mn2+

Rules:
1. Balance Oxygens by adding H2O to the side deficient in Oxygen.
2. Balance Hydrogens with a H+ ion on the deficient side of the equation.
3. Balance charge with electrons. (Key here is that the charge needs to be equal on each side, for example if the charge on one side is 2- then it has to be 2- on the other side).

Now lets do the following example:
MnO4^-1 -----> Mn2+

1. We see here that we have 4 Oxygens on the left hand side and 0 Oxygens on the right hand side.
So we must first balance the Oxygens with H2O (rule 1 above).

MnO4^-1 ------> Mn2+ + 4H2O

2. Now we have done that we can see that now we have a imbalance of Hydrogen. We have 8 Hydrogens on the right hand side and we have 0 hydrogens on the left hand side.
So we must add H+ ions to balance this out (Rule 2, as shown above).

MnO4^-1 + 8H+ ------> Mn2+ + 4H2O

3. In terms of each element everything is balanced, the only thing which isn't balanced is the charge.
We have 7+ -----> 2+.
Remember we can only balance the charge with electrons which are negative so the addition of electrons will decrease the positive charge. Therefore we add it to the left hand side. Therefore we need to add enough electrons to make 2+ charge which is seen on the right hand side from the Mn2+ ion.
(So from +7 to 2+ we need to take away 5 - thereby we need 5 electrons)

MnO4^-1 + 8H+ + 5e- -------> Mn2+ + 4H2O

Hope this made sense and thereby helped you.
Keep up the good work. Btw which exam board are you going to be Chemistry with?

Original post by HappyHylian

LOL. Quit now.

Stop acting like some arrogant dick!
They have not even started AS Chem yet!

Reply 10

Lexxaa

Original post by sim.somal

I am about to study a level chemistry and wanted to know the difficulties that you faced when studying redox reactions at AS. So that I ensure I work in those particular areas. Thank you.

Redox reactions were one of the easier topics for me, combined with oxidation numbers I actually enjoyed those questions. I didn't particularly enjoy the periodic table and Group 2 and 7 elements.
I did OCR for my exam board, I don't know about others, but oxidation numbers are not a very big topic, I learned it with a game called Chem Mahjong, sounds lame, but works.