questions

[jasoN-]

One of the many uses of H2SO4 is ammonium sulfate.

Is this the equation? I can't find it in my textbook (check the states too please)



I'm only gonna remember this one, cos no way in hell I'm remembering superphosphate  :knuppel2:



Also for calculations, can I do
n = CV
   = answer (eg. no need to do n = 1 x 2)

[toshibaj]

ammonia is a gas. other than that i think its alright.

[Martoman]

For H2SO4 I use one word: "metallurgy" because its from the Civilization  video games and I remember that.

That equation looks logical enough so long as there is an 4 on the H2S04 which i'm sure is just a  typo.

[jasoN-]

Oh yeah of course, thanks.
Also I was thinking, ammonium sulfate is a fertiliser, wouldn't it be solid then? Or it's used in a mixture or something, idk I'm not good with gardening

[Martoman]

mixed in with lots of shizz

[scocliffe09]

if you're in a rush, skip the middle line of working, if you have time, include it. Always safer to include it.
You can also form solid (NH4)2SO4 as well - depends on how you make it.

[kyzoo]

0.o wat ammonium sulfate is a product of both ammonia and sulfuric acid?

[stonecold]

Nah, this is just for application to show the uses of chemicals...

[kyzoo]

lol =/ i had no idea ammoniium sulfate is application of both ammonia and sulfuric acid X.X

[Martoman]

ZnSO4 is much easier to remember

[jasoN-]

Another question:
In the 2008 sample exam, Question 3ci, the table about change in colour.
The suggested answers (non-VCAA) says that for an increase in volume, the system becomes lighter green.
An increase in volume is equivalent to a decrease in pressure and according to Le Chatelier's, drives the forward reaction (low to high particles), hence it should become deeper green?


Also MC Q12 there's a typo, it should be 3.34 kJ / °C instead of 3.34 kJ / K


And is there an error in the 2009 VCAA exam solutions?
Question 2cii and 2ciii, they used 2 significant figures.
From the question, it should have been 3 significant figures. I used 3 and consequently had an 0.1 margin of error.
Unless they used the sig figs from part (a) which seems quite irrelevant (it is enthalpy value), they're wrong.

Thanks for any help

[matt123]

One of the many uses of H2SO4 is ammonium sulfate.

Is this the equation? I can't find it in my textbook (check the states too please)



I'm only gonna remember this one, cos no way in hell I'm remembering superphosphate  :knuppel2:



Also for calculations, can I do
n = CV
   = answer (eg. no need to do n = 1 x 2)

I always thought water was the other product.?

[will74]

Another question:
In the 2008 sample exam, Question 3ci, the table about change in colour.
The suggested answers (non-VCAA) says that for an increase in volume, the system becomes lighter green.
An increase in volume is equivalent to a decrease in pressure and according to Le Chatelier's, drives the forward reaction (low to high particles), hence it should become deeper green?


Also MC Q12 there's a typo, it should be 3.34 kJ / °C instead of 3.34 kJ / K


And is there an error in the 2009 VCAA exam solutions?
Question 2cii and 2ciii, they used 2 significant figures.
From the question, it should have been 3 significant figures. I used 3 and consequently had an 0.1 margin of error.
Unless they used the sig figs from part (a) which seems quite irrelevant (it is enthalpy value), they're wrong.

Thanks for any help

First...
An increase in volume decreases concentration of all particles therefore making a lighter green. Then, as you said the system will oppose the change and move to the right. BUT it will only partially oppose the change, as explained by Le Chateliers principle. Therefore overall, it will be a lighter green than before the external change was applied.

Second, 3.34 kJ / °C instead of 3.34 kJ / K....
They are both the same. An increase in One degree is the same as an increase in one kelvin..
e.g. 0 degrees to 1 degree = 273 K to 274 K

Third, not sure about that one, but if it should always be to the smaller number of sig figs you're using in your calculations as im aware, even if it uses an answer from above. But don't stress about it...VCAA allow +-1 error in sig figs and no marks off

Hope this helps.

[jasoN-]

OH true, yep that makes sense. thanks

[matt123]

OH true, yep that makes sense. thanks

dooood
There is water as a product in the reaction.
Just thought id point that out
well im pretty sure there is

in the notes book