Page 54 - Chemistry - XI

S. No. Experiment Observation Inference
2. Conc. H SO test
2
4
Take a little salt in (i) Colourless pungent smelling Cl −
test tube and add gas evolved which gives dense
conc. H SO and white fumes with rod dipped in
4
2
heat. NH OH.
4
(ii) Yellowish brown gas having −
pungent smell and turns starch Br

paper yellow.
(iii) Brown coloured gas evolved NO −
which turns FeSO solution dark 3
4
brown.
(iv) Violet vapours turn starch paper I −
blue.
(v) Colourless vapour having smell CH COO −
of vinegar. 3
(vi) Colourless gas with no smell and CO 2−
2 4
burns with blue fl ame.
(vii) No gas evolved. − − − −
Cl , Br , I, NO
3
2− − 2−
SO , CH COO, C O
4 3 2 4
absent

Chemical Reactions
1. Chlorides:

Cl +H SO HCl+ HSO 4
2
4
(Conc.)
2. Bromides:

2Br+ HSO 2HBr+SO 4 2
2
4
(Conc.)

2HBr + O HO + Br
2 Brown
2
(From conc.
H SO )
2 4
3. Nitrates:

2NO+ HSOConc. 2HNO +SO 2
3 2 4 3 4

6FeSO+3H SO +2HNO 3FeSO + 4H O+ 2NO
4
2
2
2
4
3
4 3

FeSO +5HO +NO FeH ONOSO

4 2 2 5 4

Brown ring
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