Which statement is not correct about fullerene C60 ?
It contains 20 six membered rings and 12 five membered rings
All carbon atoms undergo sp2 hybridisation
A six membered ring is fused with six membered rings only
A five membered ring is fused with six membered ring only
Which is the most stable allotrope of sulphur?
Octahedral sulphur
Monoclinic sulphur
Plastic sulphur
Colloidal sulphur
What is the chief constituent of pyrex glass?
B2O3
SiO2
Al2O3
Na2O
B.
SiO2
The chief constituent of pyrex glass is SiO2 . Pyrex glass is obtained by fusing 60 to 80% SiO2, 10- 25% B2O3 and remaining amount of Al2O3.
Select the most appropriate statement In BF3.
All the bonds are completely ionic.
All the bonds are covalent.
The B-F bond is partially ionic.
B-F bond has partial double bond character.
The correct formula of borax is
Na2[B4O4(OH)3].9H2O
Na2[B4O5(OH)4].8H2O
Na2[B4O6(OH)5].7H2O
Na2[B4O7(OH)6].6H2O
Which carbon is more electronegative ?
sp3 - hybridised carbon
sp - hybridised carbon
sp2 - hybridised carbon
Always same irrespective of its hybrid state