There are a series of characteristic tests for anions and cations that you need to know, like flame tests. Different exam boards require knowledge of different ones
- Exactly. And you got to the answer without having to be told.
Have a look at flame colours, and see whether you can get anywhere with it. Post back if you need any more help, or check what you've got.
Well done.
So I just need to find out what colours are visible for the following compounds after undergoing thermal decomposition or in other words what colour is it in a flame test?? Also how would you test for or identify group 2 and 7 elements
Have a look through your notes to find the flame colours produced by different metal ions. If you really can't find them, then get back to me.
Some group 2 metals can be identified by flame tests in the same way as group 1. Have a look at the compounds you're needing to differentiate and see which are in group 1 and which are in group 2. Remember too that you might NOT be able to positively identify one of them, but if you've identified the others you can do it by a process of elimination.
You can't test group 7 elements using a flame test. Why?
Have a look through your notes to find the flame colours produced by different metal ions. If you really can't find them, then get back to me.
Some group 2 metals can be identified by flame tests in the same way as group 1. Have a look at the compounds you're needing to differentiate and see which are in group 1 and which are in group 2. Remember too that you might NOT be able to positively identify one of them, but if you've identified the others you can do it by a process of elimination.
You can't test group 7 elements using a flame test. Why?
As they are halogens, could you do the first one for me as an example. Thank you for this!!
As they are halogens, could you do the first one for me as an example. Thank you for this!!
You're welcome.
Exactly! Flame tests can only test for metal ions (if you want to know the science behind it, when you heat different metals, their atoms (what they're made up of) absorb the heat as energy - they can then release this energy back, and it's released in the form of light, which is the colours that you see - different metals absorb different amounts of energy, and the colours they 'release' are consequently different too).
I don't understand what you mean about 'do the first one for you' - your list doesn't contain any halogens?! What are you referring to here?
Exactly! Flame tests can only test for metal ions (if you want to know the science behind it, when you heat different metals, their atoms (what they're made up of) absorb the heat as energy - they can then release this energy back, and it's released in the form of light, which is the colours that you see - different metals absorb different amounts of energy, and the colours they 'release' are consequently different too).
I don't understand what you mean about 'do the first one for you' - your list doesn't contain any halogens?! What are you referring to here?
I'm referring to the attachment. And so how would you test for halogens?
I'm referring to the attachment. And so how would you test for halogens?
Ok, I don't see anywhere on the powerpoint any halogens, or a mention of where you should be testing for them. Can you tell me where on this powerpoint this is mentioned?
Ok, I don't see anywhere on the powerpoint any halogens, or a mention of where you should be testing for them. Can you tell me where on this powerpoint this is mentioned?
It was just part of the task but instead I wrote it down which was how would you test for group 7 elements
It was just part of the task but instead I wrote it down which was how would you test for group 7 elements
Ah, I see
Well, there's several tests for halogens and halogen ions (=halides). Some involve heating wire wool in the presence of them - the wire wool reacts differently. Others involve their ions. Fluorine is so reactive and dangerous that you wouldn't test for that directly - it will combust pretty much anything it comes into contact with, including paper.
Without knowing your exact learning schedule, I'm not sure how much detail to give you regarding the testing of the halogens - I don't want to give you a huge amount of information you don't need.
How are you getting on identifying these metal ions?
Well, there's several tests for halogens and halogen ions (=halides). Some involve heating wire wool in the presence of them - the wire wool reacts differently. Others involve their ions. Fluorine is so reactive and dangerous that you wouldn't test for that directly - it will combust pretty much anything it comes into contact with, including paper.
Without knowing your exact learning schedule, I'm not sure how much detail to give you regarding the testing of the halogens - I don't want to give you a huge amount of information you don't need.
How are you getting on identifying these metal ions?