Silicon is :

• semi - conductor

• insulator

• conductor

• none of these

When lead nitrate is heated it produces :

• NO₂

• NO

• N₂O₅

• N₂O

Borax is used as a cleansing agent because on dissolving in water it gives

• alkaline solution

• acidic solution

• bleaching solution

• basic solution.

Inorganic graphite is :

• BN

• BF₃

• B₂H₆

• none of these

Which of the following organo - silicon compound on hydrolysis will give a three dimensional silicone ?

• R₃SiCl

• RSiCl₃

• SiCl₄

• R₂SiCl₂

Water gas is :

• CO + N₂

• CO + CO₂ + CH₄

• CO₂ + N₂

• CO + H₂

The energy gaps (E_g) between valence band and conduction band for diamond, silicon and germanium are in the order

• E_g (diamond) > E_g (silicon) > E_g (germanium)

• E_g (diamond) <E_g (silicon) <E_g (germanium)

• E_g (diamond) = E_g (silicon)= E_g (germanium)

• E_g (diamond)> E_g (germanium)> E_g (silicon).

168.

Which of the following is a carbonate ore?

• Pyrolusite

• Malachite

• Diaspore

• Cassiterite

Assertion: Silicones are hydrophobic in nature.

Reason: Si-O- Si linkages are moisture sensitive.

• If both assertion and reason are true and reason is the correct explanation of the assertion.

• If both assertion and reason are true but reason is not the correct explanation of the assertion.

• If assertion is true, but reason is false.

• Both assertion and reason are false statements.

Assertion : Borax bead test is not suitable for Al(III).

Reason : Al₂O₃ is insoluble in water.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.