Chemistry Predictions/Thoughts (3 Viewers)

[HappyTheSkibidi]

i said both will ppt but i don’t think thats right LOL

only 1 cause OH uses up the mg needed to ppt co3

 

[HappyTheSkibidi]

ngl i did that in the start i completely forgot and i’m like lowkey out of it rn so i don’t remember

I'm pretty sure it's D

We increase the volume by a factor of two which means concentration decreases no?

 

[eternallyboreduser]

i said both will ppt but i don’t think thats right LOL

magnesiuk hydroxide and another one will ppt right? i js found the qsp and showed its more than ksp and therforr it pppted

 

[nowomansland]

only 1 cause OH uses up the mg needed to ppt co3

oh i thought there was still Mg+ left after that bc i found molar solubility and subtracted rhat from mg+ added so idk

 

[Starship22]

for the Ka x Kb question, I accidentally did N2H4 + H2O —> OH- + N2H5+ so I got POH as like 4.46. How many marks would I lose for this

Cause I accidentally did it the other way around all my steps were right but it was for pOH

 

[nowomansland]

magnesiuk hydroxide and another one will ppt right? i js found the qsp and showed its more than ksp and therforr it pppted

yeah same

 

[C_master]

I'm pretty sure it's D

We increase the volume by a factor of two which means concentration decreases no?

checking with others its probably c

 

[dubbatee]

For a weak acid u look at the 1/2 equivalence point where pH=pKa, then solve for Ka
Because for 13pH to happen the conc of OH- has to be 0.1mol/L which can’t occur since some of the OH- is neutralised by the H+ from the weak acid.

I didnt sit this years HSC but im pretty sure the markers are looking for you to use the initial pH of 2.5 rather than trying to identify the half equivalence point and the corresponding pH since this may be more inaccurate

 

[C_master]

i said both will ppt but i don’t think thats right LOL

its only 1
but my dumb ass put both with no further thought thinking it was some generic ppt question

 

[t234]

Cause I accidentally did it the other way around all my steps were right but it was for pOH

so was ph 4.46 ?? and you wrote poh??

 

[nowomansland]

I didnt sit this years HSC but im pretty sure the markers are looking for you to use the initial pH of 2.5 rather than trying to identify the half equivalence point and the corresponding pH since this may be more inaccurate

oh what

 

[academicalwizard101]

i kinda got 85.7% but fudged it and made it 85.5%
why did i do that AAHHHH

i got same though 85.7% i think its right

 

[sivak23]

Did y’all get 2methylbut2ene or 2methylbutene for the last question

2-methyl but-2-ene

 

[HappyTheSkibidi]

checking with others its probably c

Nevermind you're right lmao

 

[dubbatee]

oh what

Im not saying you will lose marks for it, its just probably what they wanted + its probably the easiest/most straightforward way to do the question

 

[Starship22]

so was ph 4.46 ?? and you wrote poh??

No like o did the equation for dissociation of base instead of the acid by accident

 

[anonymoushehe]

only 1 cause OH uses up the mg needed to ppt co3

Wait so it’s one?? I said it will preferentially ppt with OH- first so I did Ksp calculation and check the remaining OH- available for Co32- and if ppt can occur with that

 

[almost_done]

Wait so it’s one?? I said it will preferentially ppt with OH- first so I did Ksp calculation and check the remaining OH- available for Co32- and if ppt can occur with that

i said MgOH2 will ppt first since Ksp is lower, and then did the calc for that. Then the left over Mg wasnt enough to form ppt with MgCO3 using Qsp < Ksp but idk if i was right or just gaslighting myself

 

[YulianaTheAmogusArtist]

what did you guys get for when the inert gas was added to the system of constant volume? was it meant to be eqm doesnt shift because volume is constant so increased pressure doesnt change the concentration of reactants or products? i think i did it wrong

 

[Geniusly]

Wait so it’s one?? I said it will preferentially ppt with OH- first so I did Ksp calculation and check the remaining OH- available for Co32- and if ppt can occur with that

I did the calculation and there is enough excess Mg2+ to precipitate with both the carbonate and hydroxide ions. I said 2.