VCE Chemistry Question Thread

[Sidha]

I was looking on VCAA and found chemistry grade distributions for 2014. It said that the minimum score for an A was 89/100 for unit 3 SACs. I'm currently averaging 87% and I've done 2 SACs, with one left for this unit. I believe I will achieve at least 89% for unit 3, but why are the cut offs so high if Chem is not considered an easy subject?

[Rishi97]

I was looking on VCAA and found chemistry grade distributions for 2014. It said that the minimum score for an A was 89/100 for unit 3 SACs. I'm currently averaging 87% and I've done 2 SACs, with one left for this unit. I believe I will achieve at least 89% for unit 3, but why are the cut offs so high if Chem is not considered an easy subject?

Last yr, more people may have done well in the exam so they had a high cut-off

[knightrider]

How would you write the electronic configuration of ?

[Redoxify]

Hi guys, my sac on wednesday is on gravimetric and volumetric analysis, we have completed the experiments in class, so what most likely will they ask on wednesday in regards to these sacs

[cosine]

A 50mL volume of 0.10M nitric acid is mixed with 60mL of calcium hydroxide solution. What volume of 0.05M sulfuric acid is required to neutralise the mixture?

Can someone just explain the process of the question, and what the role of sulfuric acid is? Also what does it mean by neutralise the solution?

Thank you

[warya]

For Mass Spectrometrey, to what extent do we need to know about free-radicals and how do you know which fragment is charged and which is a free radical

And do all nuclei present in a sample (NMR) need to be aligned against the magnetic field for the sample to be deemed in resonance?

[cosine]

Can someone please help with this one

[paper-back]

Can someone please help with this one

So we have the concentration of Cl to be 24mg/L
We can convert it to mol/L by dividing by molar mass
m(Cl)/M(Cl)=n(Cl)
24x10-3/35.5=0.000676mol/L

We know that:
MgCl2 = 2Cl+...
Therefore we can see that there are 2Cl for each MgCl2
So dividing C(Cl) by 2 gives C(MgCl2)
0.000676/2=0.000338
=3.4 x (10^-4)M (A)

[Redoxify]

in gravmetric analysis, why do we acidfy the solution before forming the precipitate?

[cosine]

A 50mL volume of 0.10M nitric acid is mixed with 60mL of calcium hydroxide solution. What volume of 0.05M sulfuric acid is required to neutralise the mixture?

Can someone just explain the process of the question, and what the role of sulfuric acid is? Also what does it mean by neutralise the solution?

Thank you

Anyone ?

[paper-back]

Anyone ?

Were you given the concentration of the Calcium hydroxide?

[knightrider]

How would you write the electronic configuration of ?

Can anyone help with this?

[cosine]

Were you given the concentration of the Calcium hydroxide?

No, that is the exact question there

[Delirium]

Hi,
We recently did a Sac on esters. Can anyone help me with these questions, Thanks.

What substance produces the odour of pentyl ethanoate. Give it a proper name and chemical formula.

And

How would you prepare an ester from acetic acid and butan-1-ol? give an equation for the reaction

[cosine]

During an acid-base titration, why do we use an indicator and how does it affect the end point?

Also how do we know what indicator to use with a specific reaction?

Thanks