the synthesis question??
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Chemistry Predictions/Thoughts (3 Viewers)
- Thread starter carrotsss
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Unovan
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Yeah but idk what you'd use other than esterification
synthesisFR
afterhscivemostlybeentrollingdonttakeitsrsly
no titrations are FREEEEE
the questions that r not free is this BS bc i have no clue how to do them (the 2021 ammonia question where they ask how much must be added or sum shi. other that that the whole paper was perfect)
the questions that r not free is this BS bc i have no clue how to do them (the 2021 ammonia question where they ask how much must be added or sum shi. other that that the whole paper was perfect)
synthesisFR
afterhscivemostlybeentrollingdonttakeitsrsly
do we get marks for not writing things on the line
e.g i wanna save space so if they have a chemical eqn in the question with its pka sometimes i write the ka next to the question but not in the working lines. is that fine?
e.g i wanna save space so if they have a chemical eqn in the question with its pka sometimes i write the ka next to the question but not in the working lines. is that fine?
probably
probs b6 idk
synthesisFR
afterhscivemostlybeentrollingdonttakeitsrsly
Hey guys so im marking my paper
can someone help teach me how to do this, its from the 2021 hsc paper. Idk like when i read the solutions it makes a lot of sense but when i was doing the calc i didn't know what to do cus i was like u need to add nitrogen gas so u do 4.5 + x but then also in equlibrium this amount then decreases bc of LCP so i didn't know where to start? idkk
Also with this one. like it seems easy u just write out ksp of the ppt and then u have the concentration of sulfate and on data sheet u have ksp so u just solve for concentration of silver then from there times by .25L to get moles then get mass so thats what i did but its. not working out?
IGNORE THE SECOND ONE I FEEL STUPID LMFAOO I WAS FINDING MAS SOF SILVER NOT SILVER NITRATE LMFAOO JOKES
can someone help teach me how to do this, its from the 2021 hsc paper. Idk like when i read the solutions it makes a lot of sense but when i was doing the calc i didn't know what to do cus i was like u need to add nitrogen gas so u do 4.5 + x but then also in equlibrium this amount then decreases bc of LCP so i didn't know where to start? idkk
Also with this one. like it seems easy u just write out ksp of the ppt and then u have the concentration of sulfate and on data sheet u have ksp so u just solve for concentration of silver then from there times by .25L to get moles then get mass so thats what i did but its. not working out?
IGNORE THE SECOND ONE I FEEL STUPID LMFAOO I WAS FINDING MAS SOF SILVER NOT SILVER NITRATE LMFAOO JOKES
Masaken
Unknown Member
ok so for q31. you're given a bunch of moles and vessel info, so i started by calculating [N2]initial, [H2]initial, [NH3]initial because we have all of that. then we chuck all of that info into an ice table. but one thing to note is that the q is asking you to increase the amount of N2 by a certain amount to increase ammonia by 0.050 moles. so for the initial concentration, you found [N2] = 0.45M. let the number of moles you add be X (don't stress too much that it's moles not concentration, the reaction vessel is a nice clean number anyway you'll see)
| Concentration (mol/L) | N2 | 3H2 | 2NH3 |
| Initial | 0.45 + X | 0.1 | 0.58 |
| Change | -0.0025 | - 0.0075 | +0.0050 moles (this bit is important, remember to divide 0.050 by 10 cos of rxn vessel) |
| Equilibrium | 0.4475 + X | 0.0925 | 0.585 |
0.4475 + X = (0.585)^2/[(0.0925)^3 x 748]
X = 0.130575... mol/L
n(N2) added to vessel = 0.130575... x 10.0L (n = cV) = 1.30575... = 1.3 mol added (2sf)
just finished this paper im not sure how they did it but basically my logic was that we know what the initial concentrations of H2 and NH3 are, and we know the change for H2 and NH3 so basically we know everything for them, whereas for N2 we know the change and what we’re trying to find the initial (or final). Note that to find the final or initial, we don’t need to use the knowledge we have of the 4.5 since that can come in later once we’re finding the difference. From there, I just let the initial for N2 be x + 0.0025 (this just makes it easier to work with) and therefore it’s final conc is x, which you can sub into the Keq formula and solve for x very easy, hence finding the final concentration and then you work backwards from there to find the addition which that indicates. dunno if that makes sense but it worked for me
you really had to post one second before me
Masaken
Unknown Member
life's a sprint, not a marathon
bf3
Masaken
Unknown Member
can't explain acidic behaviour of some non metal oxides such as SO2
synthesisFR
afterhscivemostlybeentrollingdonttakeitsrsly
it can't explain stuff like BF3
sorry to break it to u but idt hard titrations exist
wtaf is BF3
and is it explaining that it is acidic or basic or what