Predictions for Chemistry 2014 HSC? (6 Viewers)

[Queenroot]

Too generic for me Try this one pulled straight from the syllabus dotpoints that I think a lot of people will lose marks:

Describe the structure of cellulose (3)

If they don't know the answer to this then they haven't studied properly. It is one key application of condensation polymers.

Wat

Clearly you haven't watched pocohontas

 

[seventhroot]

Clearly you haven't watched pocohontas

nope :/

 

[faisalabdul16]

Whats pocohontas

 

[mreditor16]

Whats pocohontas

oh dear.

 

[Queenroot]

Whats pocohontas

 

[faisalabdul16]

That's awkward... I'm typing...

 

[seventhroot]

That's awkward... I'm typing...

You're pushing it m9

 

[faisalabdul16]

You're pushing it m9

Whats m9

 

[seventhroot]

Whats m9

The new motorway abbot announced today

 

[enigma_1]

The new motorway abbot announced today

Hahahahahaah

 

[mreditor16]

lol I'm laughing hard at you guys. let's get back on topic, before the mods ban seventh again as a scapegoat for our derailing....

 

[seventhroot]

lol I'm laughing hard at you guys. let's get back on topic, before the mods ban seventh again as a scapegoat for our derailing....

Well this was meant to be a "predictions" thread.

 

[faisalabdul16]

Too generic for me Try this one pulled straight from the syllabus dotpoints that I think a lot of people will lose marks:

Describe the structure of cellulose (3)

Getting back on topic:

Cellulose is a condensation polymer and condensation polymers are formed by the "head-to-tail" joining of two monomers which have functional groups at each end and result in the loss of a molecule, usually water. Cellulose is renewable and a polymer of which the monomer units are B(beta) glucose molecules. 'Insert drawing of cellulose'

What else can you write for 3 marks? I assume they would want to know what polymer it is and how it is formed.

 

[Queenroot]

Getting back on topic:

Cellulose is a condensation polymer and condensation polymers are formed by the "head-to-tail" joining of two monomers which have functional groups at each end and result in the loss of a molecule, usually water. Cellulose is renewable and a polymer of which the monomer units are B(beta) glucose molecules. 'Insert drawing of cellulose'

What else can you write for 3 marks? I assume they would want to know what polymer it is and how it is formed.

The 3 carbon and 4 carbon chains

 

[enigma_1]

Getting back on topic:

Cellulose is a condensation polymer and condensation polymers are formed by the "head-to-tail" joining of two monomers which have functional groups at each end and result in the loss of a molecule, usually water. Cellulose is renewable and a polymer of which the monomer units are B(beta) glucose molecules. 'Insert drawing of cellulose'

What else can you write for 3 marks? I assume they would want to know what polymer it is and how it is formed.

The loss of n-1 water molecules makes cellulose less polar this reducing it's solubility in water and coz likes dissolve likes. So it exists in plant walls coz it's insoluble in water and it's also strong because of the hydrogen bonding and strong dispersion forces due to the linear structure. It's also used in wool or something. Condensation polymerisation is fast coz it happens at both ends.

 

[faisalabdul16]

The 3 carbon and 4 carbon chains

The loss of n-1 water molecules makes cellulose less polar this reducing it's solubility in water and coz likes dissolve likes. So it exists in plant walls coz it's insoluble in water and it's also strong because of the hydrogen bonding and strong dispersion forces due to the linear structure. It's also used in wool or something. Condensation polymerisation is fast coz it happens at both ends.

oh okay fair enough

I doubt they'll ask for three marks. Nonetheless, new question.

Describe the relationship between the acidic and basic nature of oxides of elements as you move across the periodic table. 4 marks.

 

[SuchSmallHands]

oh okay fair enough

I doubt they'll ask for three marks. Nonetheless, new question.

Describe the relationship between the acidic and basic nature of oxides of elements as you move across the periodic table. 4 marks.

pH generally decreases across a period, with metal oxides generally forming basic oxides, semi-metals often forming amphoteric oxides and non-metals forming acidic oxides. However, this trend does not apply to the d-block metals, as the acidity of these metals is directly proportional to oxidation state (eg. CrO (containing Cr2+ ions) is basic, Cr2O3 (Cr3+) is amphoteric and CrO3 (Cr6+) is acidic).

I probably wouldn't include the thing about d block metals if the question was only worth two marks, but I can't think of anything else to add to make this an appropriate response for a four mark question.

 

[QZP]

pH generally decreases across a period, with metal oxides generally forming basic oxides, semi-metals often forming amphoteric oxides and non-metals forming acidic oxides. However, this trend does not apply to the d-block metals, as the acidity of these metals is directly proportional to oxidation state (eg. CrO (containing Cr2+ ions) is basic, Cr2O3 (Cr3+) is amphoteric and CrO3 (Cr6+) is acidic).

I probably wouldn't include the thing about d block metals if the question was only worth two marks, but I can't think of anything else to add to make this an appropriate response for a four mark question.

Where do you learn this stuff...

 

[SuchSmallHands]

Where do you learn this stuff...

My option is chem of art haha, I do a lot on the oxidation states of d block metals and I learned this at some point and thought it would fit in here and fill out my answer a little. If it weren't for my option I wouldn't know that, I can assure you.

 

[QZP]

Ohh nice! Yeah also I find my option (industrial) relates to back to a lot of things learned in the core.