marsenal
cHeAp bOoKs
- Joined
- Nov 12, 2002
- Messages
- 273
Going over the first module, I've got the following questions. Some a bit random, so any input on any of them would be most welcome.
1. In the practical for testing alkanes/alkenes with bromine water, what is the equation for cyclohexane + bromine water as well as the one for hexane + bromine water. In both the presence of un light and with no uv light present.
2. Independant Trial 2001 Q24 is in reference to the alkane/alkene experiment using bromine water. The question is "Identify TWO risk factors you would consider in performing risk analysis for this experiment?" Now how would you answer this question?
3. In the 2002 HSC paper, Q18(b) was "Assess current developments in the use of biopolymers. Following is my answer for this and I'm just wondering what I need to add to it to be able to get the full 5 marks for it.
A biopolymer is a naturally occuring polymer or one synthesised from naturally occuring substances. Biopolymers are becoming incresingly more important because in many situations they are excellent substitutes for materials currently obtained from the petrochemical industry, with biopolymers able to be renewable and biodegradable. these 2 traits mean that, is used in moderation they will not run out and will not cause harm to the environment. some important biopolymers include cellulose acetate, celluloid, PHA and PLA. Polylactic acid is essentially made from starch wastes. these wastes are firstly converter to simple sugars and then bacterial fermentation converts it to lactic acid. Then it is dehydrated to produce a lactide and finally it is converted to PLA using a solvent free polymerisation process. PLA is increasingly becoming a very importnat polymer due to its renewable nature and biodegradability.
4. With radioisotopes is it preferrable to have ones with high or low ionising ability for each of diagnosis and treatment. And what does the ionising ability have to do with the type of radiation produced?
5. Do we need to know about thermosetting and thermoplastics? The reason I'm asking is that there was a question about them in NEAP 2002 (Q23) and they are also mentioned in Chem Contexts 2.
6. With heats of combustion would it be correct to say that for alkanols, as the chain lenght increases (more carbons), both kJ/mol and kJ/g also rise. And also when converting between the 2, is the following correct:
kJ/mol -> kJ/g Do you divide by molar mass?
kJ/g -> kJ/mol Do you divide by number of moles?
7. How do you explain the relevant properties of PVC and polystryrene. Like why is PVC waterproof and polystyrene hard? And other properties as well.
Thanks!
1. In the practical for testing alkanes/alkenes with bromine water, what is the equation for cyclohexane + bromine water as well as the one for hexane + bromine water. In both the presence of un light and with no uv light present.
2. Independant Trial 2001 Q24 is in reference to the alkane/alkene experiment using bromine water. The question is "Identify TWO risk factors you would consider in performing risk analysis for this experiment?" Now how would you answer this question?
3. In the 2002 HSC paper, Q18(b) was "Assess current developments in the use of biopolymers. Following is my answer for this and I'm just wondering what I need to add to it to be able to get the full 5 marks for it.
A biopolymer is a naturally occuring polymer or one synthesised from naturally occuring substances. Biopolymers are becoming incresingly more important because in many situations they are excellent substitutes for materials currently obtained from the petrochemical industry, with biopolymers able to be renewable and biodegradable. these 2 traits mean that, is used in moderation they will not run out and will not cause harm to the environment. some important biopolymers include cellulose acetate, celluloid, PHA and PLA. Polylactic acid is essentially made from starch wastes. these wastes are firstly converter to simple sugars and then bacterial fermentation converts it to lactic acid. Then it is dehydrated to produce a lactide and finally it is converted to PLA using a solvent free polymerisation process. PLA is increasingly becoming a very importnat polymer due to its renewable nature and biodegradability.
4. With radioisotopes is it preferrable to have ones with high or low ionising ability for each of diagnosis and treatment. And what does the ionising ability have to do with the type of radiation produced?
5. Do we need to know about thermosetting and thermoplastics? The reason I'm asking is that there was a question about them in NEAP 2002 (Q23) and they are also mentioned in Chem Contexts 2.
6. With heats of combustion would it be correct to say that for alkanols, as the chain lenght increases (more carbons), both kJ/mol and kJ/g also rise. And also when converting between the 2, is the following correct:
kJ/mol -> kJ/g Do you divide by molar mass?
kJ/g -> kJ/mol Do you divide by number of moles?
7. How do you explain the relevant properties of PVC and polystryrene. Like why is PVC waterproof and polystyrene hard? And other properties as well.
Thanks!
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