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Chemical Bonding and Molecular Structure

Long Answer Type

251.

Why does ice float over water?

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252.

Give reasons for the following:
(i) Density of water is maximum at 277K (4°C).
(ii) Why glycerol (glycerine) is more viscous than ethyl alcohol?

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Short Answer Type

253.

Explain the formation of a chemical bond.

240 Views

Long Answer Type

254.

Write Lewis symbols for the following atoms and ions:
S and S^2–; Al and Al³⁺; H and H^–.

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Short Answer Type

255.

Define octet rule. Write its significance and limitations.

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256.

Write three favourable factors for formation of ionic bond.

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257.

Define bond length.

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Long Answer Type

258.

Explain the important aspects of resonance with reference to the $CO subscript 3 superscript 2 minus end superscript space ion. space$

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259.
Define electronegativity. How does it differ from electron gain enthalpy?

Electronegativity is defined as the tendency of an element to attract the shared pair of electrons towards itself in a covalent. The is no specific units for electronegativity.It is only a relative tendency.

Electron gain enthalpy is the energy released when one mole of the electron are added to gaseous atoms of an element. It can be negative or positive depending upon whether the electrons is added or removed. An element has a constant value of the electron gain enthalpy that can be measured experimentally.

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