“Non-stoichiometric hydrides” are :
1. | Hydrogen-deficient compounds formed by the reaction of a hydrogen atom with d-block and f-block elements. |
2. | Hydrogen-deficient compounds formed by the reaction of dihydrogen with d-block and f-block elements. |
3. | Electron-deficient compounds formed by the reaction of dihydrogen with d-block and f-block elements. |
4. | Hydrogen-deficient compounds formed by the reaction of dihydrogen with s-block and p-block elements. |
Metallic hydrides are useful for hydrogen storage because :
1. Metallic hydrides are oxygen-rich.
2. Metallic hydrides are oxygen-deficient.
3. Metallic hydrides are hydrogen-rich.
4. Metallic hydrides are hydrogen-deficient.
Atomic hydrogen or oxy-hydrogen torch is used for cutting and welding purposes because:
1. | Atomic hydrogen converts into molecular hydrogen and generates a large amount of energy. |
2. | Atomic hydrogen converts into molecular hydrogen and generates a low amount of energy. |
3. | Molecular hydrogen converts into atomic hydrogen and generates a large amount of energy. |
4. | Molecular hydrogen converts into atomic hydrogen and generates a low amount of energy. |
The correct order of hydrogen bonding among , H2O and HF, is
1. HF > >
2. > HF >
3. HF > >
4. > HF >
CO2 is used as a fire extinguisher because -
1. has high lattice energy.
2. will be effective in isolating the burning surface from dihydrogen and dioxygen.
3. is lighter than dioxygen.
4. is lighter than dihydrogen.
The term ’auto-protolysis’ of water means :
1. | Physical reaction in which two water molecules react to produce a hydroxide ion (OH–) and a hydronium ion (). |
2. | Chemical reaction in which five water molecules react to produce a hydroxide ion (OH–) and a hydronium ion (). |
3. | Chemical reaction in which two water molecules react to produce a hydroxide ion (OH–) and a hydronium ion (). |
4. | Chemical reaction in which two water molecules react to produce three hydroxide ions (OH–) |
The correct statement about the reaction of water with fluorine is:
1. | O is reduced from 0 to -1 oxidation state, whereas F is oxidized from –2 to 0 |
2. | F is reduced from 0 to -1 oxidation state, whereas O is oxidized from –2 to 0 |
3. | F is reduced from 0 to –2 oxidation state, whereas O is oxidized from – 2 to -1 |
4. | O is reduced from 0 to –2 oxidation state, whereas F is oxidized from –3 to 0 |
The structure of the common form of ice is :
1. | Each hydrogen atom is surrounded tetrahedrally by four other oxygen atoms at a distance of 540 pm. |
2. | Each hydrogen atom is surrounded tetrahedrally by four other oxygen atoms at a distance of 276 pm. |
3. | Each oxygen atom is surrounded tetrahedrally by four other oxygen atoms at a distance of 276 pm. |
4. | Each oxygen atom is surrounded tetrahedrally by four other oxygen atoms at a distance of 540 pm. |
The temporary and permanent hardness of water is caused by -
1. Permanent hardness is caused by hydrogen carbonates and temporary hardness is caused by chlorides.
2. Temporary hardness is caused by dihydrogen and permanent hardness is caused by oxides.
3. Temporary hardness is caused by insoluble hydrogen carbonates and permanent hardness is caused by chlorides.
4. Temporary hardness is caused by hydrogen carbonates and permanent hardness is caused by chlorides.
The softening of hard water by synthetic ion-exchange resins is based on -
1. Increasing the lattice energy.
2. Physical separation.
3. Lowering the activation energy.
4. Exchange of cations and anions.