1
JEE Main 2020 (Online) 7th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Oxidation number of potassium in K2O. K2O2 and KO2 respectively is :
A
+1, +2 and + 4
B
+1, +1 and + 1
C
+2, +1 and $$ + {1 \over 2}$$
D
+1, +4, and +2
2
JEE Main 2019 (Online) 12th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
An example of a disproportionation reaction is :
A
2NaBr + Cl2 $$ \to $$ 2NaCl + Br2
B
2KMnO4 $$ \to $$ 2KMnO4 + MnO2 + O2 (3) (4)
C
2CuBr $$ \to $$ CuBr2 + Cu
D
2MnO4 + 10I + 16H+ $$ \to $$ 2Mn2+ + 5I2 + 8H2O
3
JEE Main 2019 (Online) 9th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The correct order of the oxidation states of nitrogen in NO, N2O, NO2 and N2O3 is :
A
NO2 < NO < N2O3 < N2O
B
NO2 < N2O3 < NO < N2O
C
N2O < NO < N2O3 < NO2
D
N2O < N2O3 < NO < NO2
4
JEE Main 2019 (Online) 8th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
In order to oxidise a mixture of one mole of each of FeC2O4, Fe2(C2O4)3, FeSO4 and Fe2(SO4)3 in acidic medium, the number of moles of KMnO4 required is :
A
1.5
B
3
C
2
D
1
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