Multiple Choice QuestionsWhich one of the following is an example of disproportionation reaction?
3Cl2 (g) + 6OH- (aq) → ClO (aq) + 5Cl- (aq) + 3H2O (l)
Ag2+ (aq) + Ag (s) → 2Ag+ (aq)
Zn (s) + CuSO4 (aq) → Cu (s) + ZnSO4 (aq)
2KClO3 (s) → 2KCl (s) + 3O2 (g)
One mole of N2H4 loses 10 moles of electrons to form a new compound Z. Assuming that all the nitrogens appear in the new compound, what is the oxidation state of nitrogen in Z? (There is no change in die oxidation state of hydrogen.)
-1
-3
+3
+5
A 100 mL solution of 0.1 N HCl was titrated with 0.2 N NaOH solution.The titration was discontinued after adding 30 mL of NaOH solution. The remaining titration was completed by adding 025 N KOH solution. The volume of KOH required for completing the titration is
16 mL
32 mL
35 mL
70 mL
The gaseous products formed at cathode (X) and anode (Y), when an aqueous solution of sodium acetate is electrolysed are
| X | Y |
| CO2 | C2H6, H2 |
| X | Y |
| H2, CO2 | C2H6 |
| X | Y |
| H2 | C2H6, CO2 |
| X | Y |
| C2H6, H2 | CO2 |
In the chemical reaction,
Cl2 + H2S → 2HCl + S.
The oxidation number of sulphur changes from
0 to 2
2 to 0
-2 to 0
-2 to -1
In the reaction,
3Mg + N2 → Mg3N2
magnesium is reduced
magnesium is oxidised
nitrogen is oxidised
None of the above
When MnO2 is fused with KOH, a coloured compound is formed. The product and its colour is
K2MnO4, purple green
KMnO4, purple
Mn2O3, brown
Mn2O4, black
Which of the following reactions is a redox reaction?
2AgNO3 + BaCl2 → 2AgCl + Ba(NO3)2
BaO2 + H2SO4 → BaSO4 + H2O2
P2O5 + 2H2O → H4P2O7
Cu + 2AgNO3 → 2Ag + Cu(NO3)2
D.
Cu + 2AgNO3 → 2Ag + Cu(NO3)2
In reaction, Cu + 2AgNO3 → 2Ag + Cu(NO3)2
In the above reaction oxidation number of Cu change from 0 to +2. Hence, Cu is oxidised to Cu2+ and oxidation number of Ag changes from +1 to 0. Hence, Ag is reduced.
In other reactions oxidation number of element remain same before and after the reaction.
In the reaction 2Fe3+(aq) + Sn2+(aq) → 2Fe2+(aq) + A
A belongs to
Sn4+(aq)
Sn2+(aq)
Sn3+(aq)
Sn0
Switch
