HSC Chemistry Question Thread

[Sssssrr]

Every instance (not even necessarily this dot point) in the chemistry course where they asked you to draw a flow chart, you had to draw it yourself.

Yet I've never seen that dot point examined like that either. I recall writing a 7 marker on the Solvay process and its procedures but never the need to actually draw it out.

okay thanks!

[Sssssrr]

Hello, for this question can we identify (A) as starch?

out of curiosity, if this from production of materials or is it from an option topic?

[RuiAce]

Must be an option... Never seen it before in chemistry

[massive]

Hello, for this question can we identify (A) as starch?

Hey i'm pretty sure A is cellulose since the alternating glucose monomers that compose the polymer chain are inverted and this maintains its linear structure, that's why B is starch.

Not sure how correct I am, this isn't an option topic is it?

[nibblez16]

out of curiosity, if this from production of materials or is it from an option topic?

out of curiosity, if this from production of materials or is it from an option topic?

Its from Forensic chemistry   
The answer was amylose thats y i got confused...

[nibblez16]

So is there a good answer for it???

[WLalex]

When a question says... "outline the procedure you would use to..." should we simply do sentences or numbered steps?

Thanks

[massive]

guys for galvanic cells how do you figure out what electrolyte to use? Also how can you determine the colour of the electrolyte solution??

[jakesilove]

When a question says... "outline the procedure you would use to..." should we simply do sentences or numbered steps?

Thanks

You don't need to use numbered steps, but I think it is always easier to. Basically, you can do whatever you feel most comfortable with. Personally, I would use numbered steps

[jakesilove]

guys for galvanic cells how do you figure out what electrolyte to use? Also how can you determine the colour of the electrolyte solution??

You just always use the Metal Nitrate as the electrolyte in that half cell! Nitrates are always soluble, so are perfect for this use You don't actually need to know colours of electrolyte solutions, they will always give it to you. It can't hurt to know that Copper nitrate is Blue though

[kimmie]

Hey can someone help me I don't understand why the answer is part (c)

[Sanaz]

Hey Do you need to know all the batteries; lead-acid, button, dry cell, hydrogen fuel cell, lithium cell etc  or do you only need to know two for comparison? What if they are specific?

[wesadora]

Hey Do you need to know all the batteries; lead-acid, button, dry cell, hydrogen fuel cell, lithium cell etc  or do you only need to know two for comparison? What if they are specific?

You just need to know EITHER lead-acid or dry, and then another one out of that list: -fuel cell, silver button cell, lithium ion battery, etc...
so two in total.
I'm doing lead-acid and silver button and you have to know chemistry (anode, cathode, electrolyte, equations), cost/practicality (e.g. lead acid cell is cost effective supplying high voltages needed for cars, with a long life span + is rechargeable, etc.) and impacts on society/environment for each.

[WLalex]

Hey can someone help me I don't understand why the answer is part (c)

Hey! as it is a solid it will have 0 affect - that is just a rule you should know which now you do

[RuiAce]

Hey! as it is a solid it will have 0 affect - that is just a rule you should know which now you do

Not quite the answer here though

In this scenario, it is because sulfate appears:
a) in a ONE-sided equation, not reversible
b) as a PRODUCT

Sodium sulfate is guaranteed to dissolve, so it goes from solid to aqueous. It is the fact that we have a one-way reaction and not an equilibrium reaction that justifies the answer here.