• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

2023 HSC chat (23 Viewers)

U

user18181818

Active Member
Joined
Sep 12, 2023
Messages
228
Gender
Female
HSC
2023
i think it's correct
for the flame test between ba and ca don't you need to boil it or something because u can't do a flame test with them in ppt forms
 
Masaken

Masaken

Unknown Member
Joined
May 8, 2021
Messages
1,741
Location
in your walls
Gender
Female
HSC
2023
SadCeliac said:
Shocker 😭 why does everyone think I'm gay
Self explanatory question but I'm still asking

View attachment 41115
Can anyone confirm if this elimination sequence is correct - HSC 2020 Chem paper
Click to expand...
cation looks correct but tbh you could've just said flame test without having the na2so4 bit since the three cations produce three distinct results (the colours of ba2+ and ca2+ and then you just say magnesium doesn't form a distinct colour). for anion, it's not AgOH that forms the precipitate - AgOH is formed but it's not stable so it decomposes into silver oxide (silver oxide is the brown precipitate you see) so you'd need to acknowledge that. Ag+ also forms a (white) precipitate with Cl- so you'd have to acknowledge that too but apart from that everything else looks fine
 
Masaken

Masaken

Unknown Member
Joined
May 8, 2021
Messages
1,741
Location
in your walls
Gender
Female
HSC
2023
user18181818 said:
i think it's correct
for the flame test between ba and ca don't you need to boil it or something because u can't do a flame test with them in ppt forms
Click to expand...
they're all solutions though (specifies it's 0.1 mol/L at the start) so there's no ppt involved between ba2+ and ca2+
 
SadCeliac

SadCeliac

done hsc yay
Joined
Sep 23, 2021
Messages
2,490
Location
Sydney <3
Gender
Male
HSC
2023
user18181818 said:
i think it's correct
for the flame test between ba and ca don't you need to boil it or something because u can't do a flame test with them in ppt forms
Click to expand...
Ok I'll keep that in mind - flame test the ions - got it

Masaken said:
cation looks correct but tbh you could've just said flame test without having the na2so4 bit since the three cations produce three distinct results (the colours of ba2+ and ca2+ and then you just say magnesium doesn't form a distinct colour). for anion, it's not AgOH that forms the precipitate - AgOH is formed but it's not stable so it decomposes into silver oxide (silver oxide is the brown precipitate you see) so you'd need to acknowledge that. Ag+ also forms a (white) precipitate with Cl- so you'd have to acknowledge that too but apart from that everything else looks fine
Click to expand...
Okay yeah I didn't know that, and I kinda ignored the AgCl ppt because it was the final thing anyways... Also I forgot the colour lol (white yeah?)

THANKS GUYS <3 🤩
Good to know I've memorised the colours of ppts basically fully correctly
 
U

user18181818

Active Member
Joined
Sep 12, 2023
Messages
228
Gender
Female
HSC
2023
Masaken said:
they're all solutions though (specifies it's 0.1 mol/L at the start) so there's no ppt involved between ba2+ and ca2+
Click to expand...
yeah but then he's adding sulfate to it to make a ppt right? or you could take a new solution and do the flame test
 
S

Sam14113

Member
Joined
Aug 22, 2021
Messages
93
Gender
Male
HSC
2023
carrotsss said:
idk my english teacher seems like extremely confident ill b6 - she reckons im gonna get the second highest hsc mark in my yeargroup (we usually get 4-6 b6 for context) which is nice but idk if it’s like a false confidence
Click to expand...
How are you like almost SR in like every STEM subject there is and then are suddenly crazy at English as well?
 
You must log in or register to reply here.

Users Who Are Viewing This Thread (Users: 0, Guests: 23)

Top