help with past HSC paper questions (1 Viewer)

[mishy89]

i need help with a few questions from past HSC papers but i dont know what year they are from.

- Assess current developments in the use of biopolymers.

- Explain why alkanes and their corresponding alkenes have similar properties, but very different chemical properties.

- Name one type of cell, other than dry cell or lead-acid cell. Evaluate it in comparison with either the dry cell or lead-acid cell, in terms of chemistry and the impact on society. Include relevant equations.

Does anybody know if these questions are in a certain year? and if it is..then what year is it in..? or do u know where to get the solutions to this?
thanx. i need it asap

 

[Dreamerish*~]

It's very difficult to find good ready-to-download answers for past papers. The marker's guides aren't helpful at all. They focus on what the students failed to do rather than what they did that was correct.

- Assess current developments in the use of biopolymers.

You would choose a specific polymer and talk about it. Give examples of other biopolymers too. Then point out the stumbling blocks - i.e. what is preventing large-scale production of these biopolymers? These could be disadvantages such as cost and efficiency. Sum up with a line or two, making it clear how successful the biopolymer industry has been in replacing non-biodegradable material.

- Explain why alkanes and their corresponding alkenes have similar properties, but very different chemical properties.

This is because alkenes are unsaturated compounds - they have a double bond which make them a lot more reactive than the saturated alkanes. Because of this, alkenes readily undergo addition reactions to form other substances, while alkanes can only undergo substitution reactions with certain compounds under certain conditions (e.g. reacting with chlorine in the presence of U.V. radiation).

However, alkanes and their corresponding alkenes have very similar boiling and melting points (physical properties) because these properties depend on the intermolecular, not intramolecular forces. Alkanes and corresponding alkenes have very similar atomic masses, and are non-polar compounds. Hence the only intermolecular force present are weak dispersion forces.

- Name one type of cell, other than dry cell or lead-acid cell. Evaluate it in comparison with either the dry cell or lead-acid cell, in terms of chemistry and the impact on society. Include relevant equations.

You can look this up in a textbook. I did the silver-oxide (button) cell which I found relatively easy. You should include in your answer the anode and cathode reactions, and shorthand diagrams.

By comparing the environmental impacts, you focus on the chemicals used in the cells, and those that are released by the cells once they are thrown away. For example, the alkaline cell presents a more severe environmental problem than the zinc-carbon cell, because alkaline waste is more dangerous to waterways. Impacts on society means the size of the cell, how long it lasts, and what appliances it is suitable for.

I've answered all of these questions when I was going through past papers during the HSC. Just use all the information in your head. Write as much as you can (during the limited time) and make sure you don't contradict yourself. For these types of questions, you can choose to put them into dot points. For the battery question, a table may be appropriate.

 

[LostAuzzie]

Assess current developments in the use of biopolymers

There were a lot of problems when our class had this in our half-yearlies because the Syllabus refers to a specific biopolymer and most of us answered with regards to just one.
Anyways it was in the 2002 paper and I would answer it by talking about the uses based on properties of a specific biopolymer and briefly referring to the uses of a few others.

Explain why alkanes and their corresponding alkenes have similar properties, but very different chemical properties

This was also in the 2002 paper, you would talk about intermolecular forces (which affect physical properties) being similar while bonding between molecules (affecting chemical properties) is different based on alkenes having at least one reactive double bond which Alkanes do not.

Name one type of cell, other than dry cell or lead-acid cell. Evaluate it in comparison with either the dry cell or lead-acid cell, in terms of chemistry and the impact on society. Include relevant equations

Was in the 2001 HSC Paper, basically you write half equations for the anode and cathode as well as what each is made of and what the electrolyte is, a balanced overall chemical equation would also be helpful. With regards to impact on society id refer to its uses and how these affect society

Hope that helps

EDIT: Damnit Dreamerish beat me to it

 

[mishy89]

ahaha thanx guyz! btw i found a good site which has solutions for the past HSC paper for 2001! it has examples of band 5/6 answerz. its realli good. but i dont have it for the other years. just 2001. im trying to look for 2002 but i cant find it..anywaiz! u guys can use that site to look at the past HSC paper of 2001 as it has questions and solutionz!

 

[LostAuzzie]

ahaha thanx guyz! btw i found a good site which has solutions for the past HSC paper for 2001! it has examples of band 5/6 answerz. its realli good. but i dont have it for the other years. just 2001. im trying to look for 2002 but i cant find it..anywaiz! u guys can use that site to look at the past HSC paper of 2001 as it has questions and solutionz!

I've got the HSC Success One, which has the past HSC papers and solutions, you should get your school to bulk buy the ones for this year, it will have the 2005 paper as well

 

[mishy89]

hmmm yeh but my skool wont do that! lol i'll probably borrow it from the libary sumwhere! fanxx agen

 

[mishy89]

does anyone have the solutions to the 2002 past HSC papers??

 

[richz]

Just get the success one book all the answers to past hsc papers are in their.

For the biopolymer check the PoM section of the success one book it has some good pts. also some pts to consider for PHB:
-Used in medical sutures and shampoo bottles becuz it is biodegradable and non toxic
-prices are still too high .'. not viable, until the process is improved, PHB will not be used frequently

and for the battery i found sumthing in the resources section that mite help:

bah file is too big. I'll email it to u. Wats ur email?

 

[mishy89]

ahaha fanx dw bout it! i got itz..but ummm i was wondering if anyone knows the answer for the question in the 2002 HSC paper. i think it is question 18
Name the type of polymerisation shown in the following reaction. but i dont have the picture to show you..if u got the paper then can u plz reply with the answer for that asap. thanx heapz!

 

[richz]

condensation polymerisation, because a smaller molecule is condensed out of the process ie. H2O

 

[funnybunny]

"Assess current developments in the use of biopolymers.'
umm..thats not in the syllabus anymore..u used 2 hav 2 research a few biopolymers.. but now u only need to know 1 in detail (eg. PHB) and the potential impact of biopolymers on society..

 

[richz]

yes i know but it is still realted to a dot pt

 

[mishy89]

ahahaha alryt denz! fanx!