HELP! Chemistry Paper has me confused!!

Watch
This discussion is closed.
mubinchoudhury
Badges: 0
#1
Report Thread starter 17 years ago
#1
undefinedundefined
I found this question in a paper3b specimen paper for As Chemistry from Edexcel.

Compound C contains an ion and cation. Certain tests were carried out on the compound:

Tests:

a) Flame Test

Result: light green coloured flame

b) Heat on C

Result: Brown Gas Evolved
Relights glowing splint

c) Dissolve C in Water

Result colourless solution

d) Add dilute Sulphuric Acid to a solution of C

Result: White ppt.

e) Add excess NaOH to the solution of C

Result: Faint white ppt. insoluble in excess



The question requires me to fill in the inferences. I know that a) indicates the presence of barium ions. b) suggests bromide ions are present and oxygen was evolved. d) confirms the presence of Barium ions, however I have no idea what to infer from c) and e). I am aware that the compund is Barium Bromate.

Thanks in advance for any help
0
The Albatross
Badges: 12
Rep:
?
#2
Report 17 years ago
#2
(Original post by mubinchoudhury)
I found this question in a paper3b specimen paper for As Chemistry from Edexcel.

Compound C contains an ion and cation. Certain tests were carried out on the compound:

Tests:

a) Flame Test

Result: light green coloured flame

b) Heat on C

Result: Brown Gas Evolved
Relights glowing splint
Brown gas: could be NO2. Relights glowing splint: definately oxygen. The nitrates of group 2 produce both these gases on heating

c) Dissolve C in Water

Result colourless solution
sorry, not sure what this would infer Yes of course I do. See below :rolleyes:

d) Add dilute Sulphuric Acid to a solution of C

Result: White ppt.

e) Add excess NaOH to the solution of C

Result: Faint white ppt. insoluble in excess
Could be Mg Li Ba Sr or Ca


The question requires me to fill in the inferences. I know that a) indicates the presence of barium ions. b) suggests bromide ions are present and oxygen was evolved. d) confirms the presence of Barium ions, however I have no idea what to infer from c) and e). I am aware that the compund is Barium Bromate.

Thanks in advance for any help
Cation: definately Barium
Anion: Could be nitrate (NO3-)

Hope this helps!
0
Ralfskini
Badges: 10
Rep:
?
#3
Report 17 years ago
#3
The inference from c) is that the metal ion is not a transition metal and the salt is soluble.
0
hornblower
Badges: 6
Rep:
?
#4
Report 17 years ago
#4
It's barium nitrate.
0
The Albatross
Badges: 12
Rep:
?
#5
Report 17 years ago
#5
(Original post by Ralfskini)
The inference from c) is that the metal ion is not a transition metal and the salt is soluble.
Of course! *bangs forehead on desk repeatedly* I should know that. Uncoloured solution: not a d block ion.
0
X
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Feeling behind at school/college? What is the best thing your teachers could to help you catch up?

Extra compulsory independent learning activities (eg, homework tasks) (4)
4.26%
Run extra compulsory lessons or workshops (14)
14.89%
Focus on making the normal lesson time with them as high quality as possible (18)
19.15%
Focus on making the normal learning resources as high quality/accessible as possible (10)
10.64%
Provide extra optional activities, lessons and/or workshops (31)
32.98%
Assess students, decide who needs extra support and focus on these students (17)
18.09%

Watched Threads

View All