FSN Chemistry Unit 4 Exam - Answers (By Collin)

[Collin Li]

Question 20 is wrong - it's C, not D. I interpreted it a different way.

I have maintained it was C from the beginning. Did you choose D?

[Khangfu]

I choose C but mhs is against me XD. Then i got the explanation which makes complete sense.

[Collin Li]

Amount of energy in coal----> many transformation---> electricity. Least amount fo energy from coal
Amount of energy from steam---> mechanical ---> electrical not alot fo energy from steam to electrical
Mechanical --> electrical.

 The question asked for the amount of energy in each form converted to electrical. Not how much energy was in the coal initially, in each form... so the chemical energy, a lot of it will be lost and yeah. Really annoying. I know what your saying, that coal has most energy, however most of this energy is lost as waste heat. Not all is converted to electricity. They key is to identify how much of each energy was converted to electricity so basically efficiency.

There's no way your interpretation makes sense, since the question says:
"The amount of energy in each of these forms that take part in the generation of a fixed quantity of electricity is, from lowest to highest."

For a fixed quantity of electricity, the amount of energy is 100% from the coal, steam and the turbine, it's just that the coal, steam and turbine also produced other forms of energy.

We actually need to find out, for a fixed quantity of electricity, how much input do we need of each form of energy so that we will get that same fixed quantity of electricity. This then answers the question: which forms of energy require the most "energy input" in order to yield the fixed quantity of electricity we are supposed to produce.

This is the explanation that makes complete sense, IMO. I reckon MHS is wrong. I'm an ex-MHS guy, I'm better than you guys, mwahahaha! (Just kidding, *meep* don't hurt me plz)

[Khangfu]

Amount of energy in coal----> many transformation---> electricity. Least amount fo energy from coal
Amount of energy from steam---> mechanical ---> electrical not alot fo energy from steam to electrical
Mechanical --> electrical.

 The question asked for the amount of energy in each form converted to electrical. Not how much energy was in the coal initially, in each form... so the chemical energy, a lot of it will be lost and yeah. Really annoying. I know what your saying, that coal has most energy, however most of this energy is lost as waste heat. Not all is converted to electricity. They key is to identify how much of each energy was converted to electricity so basically efficiency.

There's no way your interpretation makes sense, since the question says:
"The amount of energy in each of these forms that take part in the generation of a fixed quantity of electricity is, from lowest to highest."

For a fixed quantity of electricity, the amount of energy is 100% from the coal, steam and the turbine, it's just that the coal, steam and turbine also produced other forms of energy.

We actually need to find out, for a fixed quantity of electricity, how much input do we need of each form of energy so that we will get that same fixed quantity of electricity. This then answers the question: which forms of energy require the most "energy input" in order to yield the fixed quantity of electricity we are supposed to produce.

This is the explanation that makes complete sense, IMO. I reckon MHS is wrong. I'm an ex-MHS guy, I'm better than you guys, mwahahaha! (Just kidding, *meep* don't hurt me plz)

im not from mhs XD i just discussed answer with friend dere

[cara.mel]

khangfu I interpreted it the same way as you =P
I'm under the impression we're wrong, C's right. Oh well.
Doubt they'd accept both answers unless our side got some serious weight behind it
I don't care too much about it but.

[costargh]

I've got my money on Coblin purely because he's Coblin.  

[root]

The answers need a little modification. The liethicin molecule contained 2 ionic section, which would be resposible for the attraction to water. So ionic half would be more correct than polar half, i think.

[Collin Li]

The answers need a little modification. The liethicin molecule contained 2 ionic section, which would be resposible for the attraction to water. So ionic half would be more correct than polar half, i think.

I don't have the picture of the exam with me, but I think I vaguely remember that. You are correct, but I don't think they'd take marks off for merely saying polar. You're right though, I should be talking about "electrostatic indifference" on one side (the non-polar neutral side) vs the "electrostatically interactive" side (the polar and charged sides).

[kingmar]

No, MHS didn't say that.

MHS teachers maintain it is C. You asked the wrong representative of MHS.

EDIT: Good work coblin. You've vindicated my answers. Now, I'll wait till Dec. 17th and collect.

[AhaShake]

Alrighty sweet. Lost 2 marks it looks like. 1 for the pH (which now is obvious) of the standard hydrogen cell. And another for seeing Tl as Ti and writing Ti. Fantastic.

Also since that question about the magnitude of delta H said magnitude, is it essential to have the - at the front? I can't remember if i put it there or not.

[Collin Li]

Alrighty sweet. Lost 2 marks it looks like. 1 for the pH (which now is obvious) of the standard hydrogen cell. And another for seeing Tl as Ti and writing Ti. Fantastic.

Also since that question about the magnitude of delta H said magnitude, is it essential to have the - at the front? I can't remember if i put it there or not.

A blind examiner could mark your Ti correct.

If it said magnitude, you really shouldn't have the - in front, so you should be fine. I didn't see that.

[Khangfu]

No, MHS didn't say that.

MHS teachers maintain it is C. You asked the wrong representative of MHS.

EDIT: Good work coblin. You've vindicated my answers. Now, I'll wait till Dec. 17th and collect.

i maintained that i only checked answer with friends =P

[Mao]

reading the question, C is the most plausible answer, it can be comprehended as "the amount of mechanical/thermal/chemical energy that were present during the process of generating a certain amount of electricity", hence mechanical<thermal<chemical

and just btw what is MHS?

oh wait, melbourne high, right...

now i cbf deleting what i just written, and my cursor is hovering above "submit"

[Collin Li]

reading the question, C is the most plausible answer, it can be comprehended as "the amount of mechanical/thermal/chemical energy that were present during the process of generating a certain amount of electricity", hence mechanical<thermal<chemical

and just btw what is MHS?

oh wait, melbourne high, right...

now i cbf deleting what i just written, and my cursor is hovering above "submit"

Typing is easier than backspacing. I could just type on foerever and ever, never fixing these fucking typos that I make...

ok fine i'll fcollin says (18:24):
did u do well or not
collin says (18:24):
(and did u pick up bitchez)

wtf..

LOL!

[Ahmad]

collin says:
did u do well or not
collin says:
(and did u pick up bitchez)
φ-Ahmad - says:
well all my answers are right
φ-Ahmad - says:
but i feel veeery sick
φ-Ahmad - says:
i was literally about to faint
φ-Ahmad - says:
dizzy
collin says:
fuck nice