I have a few questions in chemistry-
1) Transition metals - why does the Fe2+ have electrons in on the d-orbital, what as the 4s orbital?
2) Does anyone have notes on how to interpret the practical data? Like infra red, etc. My text book tells how they work but not how to interpret the data which is what I actually need. If so can you PM me or tell me here so I can PM you with my email?
3) Optical isomerism - What does being optically active mean? And if optical isomers have the same physical and chemical properties, why do they matter? Why should we care about the orientation of the molecules?
There are more coming later. Any and all help appreciated. My exam is in 3 days so I'm a little deperate here.
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Edexcel Unit 4 and 5 questions watch
- Thread Starter
- 09-06-2008 11:04
Offline17ReputationRep:Community AssistantStudy Helper
- Community Assistant
- Study Helper
- 09-06-2008 11:16
1. Transition metals always lose the 4s electrons first when forming ions.
3. Rotates the plane of polarised light. They can have different chemical properties when reacting with other optical isomers (key and lock theory). Very important in biochemistry
- 09-06-2008 14:12
I can only answer a little bit on the third question:
You don't need to know the use or significance of the compound's orientation, the physical and chemistry properties of those optical isomers. They are not in the edexcel syllabus. There's no harm knowing it but since you only have 3 days left, i wouldn't advice you to know things that are not going to give you any marks in the real exam. When you are asked to explain optical isomerism in the real exam, you need to specify a few things:
1) The compound has is chiral/carbon atom attached to four different groups of atom(s)
2) They exhibit non-superimposable mirror image.
3) Roatates the plane of polarised monochromatic light.
- 11-06-2008 12:23
It's like your hand really.
Your left hand is a mirror image of your right hand but if you placed your left hand on the back of your right hand the two wouldn't superimpose because your two thumbs would stick out either side.
It's similar for optical isomers: they have mirror images that don't superimpose.