CBSE
The reaction that takes place when Cl2 gas is passed through conc. NaOH solution is
oxidation
reduction
displacement
disproportionation
The oxidation number of carbon in CH2O is:
-2
+2
0
+4
The oxidation state of C in C6H12O6 is
+6
-6
0
+4
Excess of KI reacts with CuSO4 solution and then Na2S2O3 solution is added to it. Which of the statements is incorrect for this reaction ?
Cu2I2 is formed
CuI2 is formed
Na2S2O3 is oxidised
Evolved I2 is reduced
Which of the following reaction involves oxidation and reduction?
NaBr + HCl → NaCl + HBr
HBr + AgNO3 → AgBr + HNO3
H2 + Br2 → 2HBr
Na2O + H2SO4 → Na2SO4 + H2O
The brown complex obtained in the detection of nitrate radical is formulated as [Fe(H2O)5NO]SO4. What is the oxidation number of Fe in this complex?
+1
+2
+3
0
When a manganous salt is fused with a mixture of KNO3 and solid NaOH, the oxidation number of Mn changes from +2 to
+4
+3
+6
+7
If Cl2 is passed through hot aqueous NaOH, the products formed have Cl in different oxidation states. These are indicated as
-1 and +1
-1 and +5
+1 and +5
-1 and +3
Which of the following reactions are disproportionation reaction?
(a) 2Cu+ → Cu2+ + Cu0
(b) 3MnO
(c) 2KMnO4
(d) 2MnO
Select the correct option from the following
(a), (b) and (c)
(a), (c) and (d)
(a) and (d) only
(a) and (b) only