Page 61 - Chemistry - XI
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FeSO +NO+5H O FeH ONOSO
4 2 2 5 4
Brown ring
(b) KMnO test:
4
2KMnO+3H SO +5NO KSO+ 2MnSO+5NO+ HO
4 2 4 2 2 4 4 3 2
(c) Diphenyl amine test:
2C H NH +O CH NN CH +H O
6
2
6
6
5 2
From nitrite 5 2 Deep blue 5 2
(d) Starch-iodide test:
NO +H SO HSO+ HNO
2 2 4 4 2
2KI+2HNO +2HSO 2KHSO+ I+ 2NO+ 2H O
2 2 4 4 2 2
I ++Starch Deep blue complex
2
5. Test for NO − 3
(a) Ring test:
NO +H SO HSO+ HNO
3 2 4 4 3
2FeSO+ 2HNO +H SO Fe SO +2HO +2NO
4 3 2 4 2 4 3 2
F FeSO +NO+5H O FeH ONOSO
4 2 2 5 4
Brown ring
(b) Copper turning test:
NO +H SO HSO+ HNO
3 2 4 4 3
Cu +4HNO Cu NO +2HO +2NO
3 3 2 2 2
6. Test for Cl –
(a) AgNO test:
3
Cl +AgNO AgCl+NO
3 3
White ppt.
AgCl+2NH OH Ag NH Cl+ 22H O
4 3 2 2
S oluble
(b) MnO test:
2
Cl +H SO HCl+ HSO 4
2
4
Conc.
MnO+ 4HCl MnCl +2H OO+Cl
2 2 2 2
Greenish yellow
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