Which of the following does not contain silicon?

• Kaoline

• Agate

• Ruby

• Quartz

12.

Willemite is

• Zn₂SiO₄

• H₂PtCl₆

• ZnO

• ZnOFe₂O₃

The common basic structural unit in silicates and silica is

• ${\mathrm{SiO}}_6^{4-}$

• ${\mathrm{SiO}}_3^{2-}$

• ${\mathrm{SiO}}_4^{4-}$

• ${\mathrm{Si}}_2{\mathrm{O}}_7^{6-}$

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

The element that does not form acidic oxide is

• carbon

• phosphorus

• chlorine

• barium

What is the chief constituent of pyrex glass?

• B₂O₃

• SiO₂

• Al₂O₃

• Na₂O

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