The basic structural unit of silicates is

• SiO^-

• ${\mathrm{SiO}}_4^{4-}$

• ${\mathrm{SiO}}_3^{2-}$

• ${\mathrm{SiO}}_4^{2-}$

Which of the following is electron deficient?

• (CH₃)₂

• (SiH₃)₂

• (BH₃)₂

• PH₃

Which of these is not a monomer for a high molecular mass silicone polymer?

• MeSiCl₃

• Me₂SiCl₂

• Me₃SiCl

• PhSiCl₃

Which of the following statements regarding ozone is not correct? 

• The ozone molecule is angular in shape.

• The ozone is a resonance hybrid of two structures. 

• The oxygen-oxygen bond length in ozone is identical with that of molecular oxygen

• Ozone is used as germicide and disinfectant for the purification of air

Which of the following statements is not correct?

• Silicon is extensively used as a semiconductor

• Carborundum is SiC

• Silicon occurs in free state in nature

• Mica contains the element silicon

The purest form of coal is :

• peat

• anthracite

• bituminous

• lignite

BCl₃ + H₂O$\to$X, the products formed in the reaction are

• B₂O₃ + HOCl

• H₃BO₃ + HCl

• B₂H₆ + HCl

• no reaction

78.

The borax bead test the coloured ions give characteristic coloured beads due to formation of

• metal borates

• metal metaborates

• metal phosphates

• metal tetraborates

Which of the following is used in making rinter's ink, shoe polish, black varnish and paint?

• Lamp black

• Bone black

• Carbon black

• None of these

CO is poisnous gas, antidote for CO poisoning is

• carborundum

• carbogen

• corbonic acid

• pure oxygen