Chemistry unit 2 6CH02 exam.How was it?

[alex]

I don't think that was one of the choices lol... they were;
A) intermolecular forces in water are stronger than that in hexane
B) the hexane molecules can't get in between the ions
C) energy is released when the ions are hydrated
D) the sodium and chloride ions can form hydrogen bonds with the water
... so I'm guessing you went for C?
That makes sense about the acid!
And I don't mean for the titration, I mean for the one about chlorine and bromine! xD

ohh.. it was a multiple choice? i forgot. I guess i chose C but i ain't sure

For the observation i wrote: red-brown fumes formed which condense to form a red-brown liquid
if we are talking about the reaction of chlorine with bromine

 

[livlivliv]

ohh.. it was a multiple choice? i forgot. I guess i chose C but i ain't sure

For the observation i wrote: red-brown fumes formed which condense to form a red-brown liquid
if we are talking about the reaction of chlorine with bromine

lol haha xD
oh dear i think i put colourless to orange...

 

[georgewest28]

I don't think that was one of the choices lol... they were;
A) intermolecular forces in water are stronger than that in hexane
B) the hexane molecules can't get in between the ions
C) energy is released when the ions are hydrated
D) the sodium and chloride ions can form hydrogen bonds with the water
... so I'm guessing you went for C?
That makes sense about the acid!
And I don't mean for the titration, I mean for the one about chlorine and bromine! xD

yeah i gave you my answer for the cl and br one

 

[livlivliv]

guys it said suggest the mechanism, calm down!
and i put for the sodium chloride one thaty hexane cant get between the ions. then
for the HCL one, HCL disscoiates in H+ and cl- in solution, clocking the correct attracted cathode/anode if you get me..
the colour change was orange to colourless as you were going from bromine water to chlorine water

weren't we going from chlorine water to bromine water tho? :O

 

[georgewest28]

hm, maybe, either way im sure i know my colours

 

[alex]

lol haha xD
oh dear i think i put colourless to orange...

yes, there is a color change , but the final color is not orange. They might accept it but the actual color is red-brown

weren't we going from chlorine water to bromine water tho? :O

Yes, bromine can't displace the chloride ion out of its compounds (bromine is a worse oxidising agent than chlorine)

 

[georgewest28]

yes, there is a color change , but the final color is not orange. They might accept it but the actual color is red-brown



Yes, bromine can't displace the chloride ion out of its compounds (bromine is a worse oxidising agent than chlorine)

file mou, im sure bromine water is orange

 

[livlivliv]

yes, there is a color change , but the final color is not orange. They might accept it but the actual color is red-brown
Yes, bromine can't displace the chloride ion out of its compounds (bromine is a worse oxidising agent than chlorine)

It's not definitely red-brown. CGP says orange and my teacher said orange. they usually accept a range of colours tho

 

[alex]

file mou, im sure bromine water is orange

hmm.. to vivlio m says red :S

It's not definitely red-brown. CGP says orange and my teacher said orange. they usually accept a range of colours tho

^this. they accept a range of colors

 

[livlivliv]

hmm.. to vivlio m says red :S



^this. they accept a range of colors

what did you get for the ppm?

 

[alex]

^i dont remember. It was higher than the one given in the question which shows that it is richer than the other one but i dont remember the exact number

 

[livlivliv]

i

^i dont remember. It was higher than the one given in the question which shows that it is richer than the other one but i dont remember the exact number

2200???

 

[georgewest28]

hmm.. to vivlio m says red :S



^this. they accept a range of colors

to vivlio mou says orange haha, think of the decolorisation of bromine water when shook with an alkene!

 

[alex]

to vivlio mou says orange haha, think of the decolorisation of bromine water when shook with an alkene!

yepp.. i always wrote from red-brown to colorless


edit:checked previous mark schemes

They literally accept every shade of brown/orange there is

 

[alex]

i
2200???

i think but i am not sure. It kinda rings a bell

 

[livlivliv]

i think but i am not sure. It kinda rings a bell

Good!

 

[jtbteddy]

What did you get for the perccentage of zinc in the marble sort of thing? was it like 13% and were the moles of sodium thiosulfate like 0.016 or something?,

 

[livlivliv]

What did you get for the perccentage of zinc in the marble sort of thing? was it like 13% and were the moles of sodium thiosulfate like 0.016 or something?,

I think I got 13.8%

 

[georgewest28]

the test for mg and barium, what did you choose? limewater and shake?

 

[livlivliv]

the test for mg and barium, what did you choose? limewater and shake?

I said flame test