formation involves large quantity of heat evolution which makes its use in:
1. deoxidizer
2. confectionary
3. indoor photography
4. thermite welding
Al and Ga have the same covalent radii because of:
1. Greater shielding power of s-electrons of Ga atoms
2. Poor shielding power of s-electrons of Ga atoms
3. Poor shielding power of d-electrons of Ga atoms
4. Greater shielding power of d-electrons of Ga atoms
Which is used as mordant?
1.
2.
3.
4.
Hybridisation of boron in diborane is:
1.
2.
3.
4.
The blue coloured mineral 'Lapis Lazuli' used as semi precious stone is:
1. sodium alumino silicate
2. zinc cobaltate
3. prussian blue
4. basic copper carbonate
Boron carbide, is widely used for:
1. making acetylene
2. making plaster of Paris
3. as a hardest substance after diamond
4. making boric acid
Which one is explosive?
1.
2.
3.
4.
does not exist as dimer but exist as dimer because:
1.chlorine is more electronegative than hydrogen
2.there is back bonding in but does not contain such multiple bonding
3.large sized chlorine atoms do not fit in between the small boron atoms whereas small sized hydrogen atoms get fitted between boron atoms
4.none of the above
Which of the following imparts green colour to flame?
1.
2.
3.
4.