The pair that on reaction will not evolve gas is
1. Copper and HCl (aqueous)
2. Iron and steam
3. Iron and (aqueous)
4. Sodium and ethyl alcohol
on oxidation gives:
1.
2.
3.
4.
Pure water can be obtained from sea water by:
1. Centrifugation
2. Plasmolysis
3. Reverse osmosis
4. Sedimentation
The isotopes of hydrogen and their mass ratio are -
1. Protium, Deuterium, Tritium ; 3:2:3
2. Protium, Deuterium, Tritium ; 1:2:3
3. Protium, Deuterium, Tritium ; 2:2:3
4. Protium, Deuterium, Tritium ; 3:2:1
Hydrogen exists in diatomic form rather than monoatomic form under normal conditions -
1. Due to high ionization enthalpy
2. Due to low ionization enthalpy
3. Due to high electron gain enthalpy
4. Due to low electron gain enthalpy
The role of an electrolyte in the preparation of H2 by electrolytic method is:
1. | It lowers the availability of ions available in the process for the conduction of electricity. |
2. | It makes the ions available in the process for conduction of electricity. |
3. | It cools down the temperature. |
4. | None of the above |
The products obtained on the completion of the following reactions (i) and (ii) respectively are :
i. | C3H8(g) + 3H2O(g) \(\xrightarrow[Catalyst]{\Delta}\) A |
ii. | \(\mathrm{Zn}_{(s)}+\mathrm{NaOH}_{(\mathrm{aq})} \xrightarrow[]{Heat}\)B |
1. A = CO, and H2 ; B = Na2ZnO2
2. A = CO2 ; B = Na4ZnO4
3. A = CH3CH2CH2OH ; B= ZnO
4. None of the above
The consequences of high enthalpy of H–H bond in dihydrogen is /are :
1. | Hydrogen has a low tendency to form ions. |
2. | It forms diatomic molecules (), and a large number of covalent hydrides. |
3. | Hydrogen does not possess metallic characteristics. |
4. | All of the above. |
The correct statement about electron-deficient hydride is that it:
1. | Does not have sufficient electrons to form a regular bond. |
2. | Cannot be represented by conventional Lewis structures. |
3. | Accept electrons. |
4. | All of the above. |
The hydrides of carbon (CnH2n + 2) can act as -
1. Lewis acid.
2. Lewis base.
3. Both 1 and 2
4. None of the above