When SO2 is passed through acidified solution of potassium dichromate, then chromium sulphate is formed. The change in oxidation number of chromium is:
1. +4 to+2
2. +5 to+3
3. +6 to+3
4. +7 to+2
In the reaction;
2Ag + 2H2SO4 Ag2SO4 + 2H2O + SO2, H2SO4 acts as:
1. Oxidizing agent
2. Reducing agent
3. Dehydrating agent
4. None of the above
Which of the following shows the highest oxidation number in the combined state?
1. Os
2. Ru
3. Xe
4. All of the above
In the preparation of chlorine from HCl; MnO2 acts as:
1. Reducing agent
2. Oxidising agent
3. Catalytic agent
4. Dehydrating agent
In the equation,
N + H2O N + 2H+ + ne-
n represents
1. 5
2. 1
3. 2
4. 3
Reaction between acidified K2Cr2O7 and iron (II) ions shown by the equation:
Cr2(aq) + 6Fe2+(aq) +14H+(aq)2Cr3+(aq) + 7H2O(l) + 6Fe3+(aq)
The correct statement among the following is -
1. Colour of the solution changes from green to blue
2. Iron (II) ions are reduced
3. Dichromate ions are reduced
4. Hydrogen ions are reduced
Which metal exhibits more than one oxidation states?
1. Na
2. Mg
3. Al
4. Fe
Among the following, In which iron has the lowest oxidation state?
1. Fe(CO)5
2. Fe2O
3. K4Fe(CN)6
4. FeSO4.(NH4)2SO4.6H2O
When an acidified solution of ferrous ammonium sulphate is treated with KMnO4 solution, the ion that gets oxidised is:
1. Fe2+
2. S
3. N
4. Mn
2Na2S2O3 + I2 Na2S4O6 + 2NaI,
the oxidation state of sulphur in tha above reaction:
1. Decreases
2. Increases
3. Remain unchanged
4. None of the above