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प्रश्न
Give reason for the following:
Covalent compounds have a low melting and boiling point.
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उत्तर
Covalent compounds are held together by modest intramolecular forces. As a result, breaking the bonds between two or more molecules requires only a minimal amount of energy.
Therefore, these compounds have low melting and boiling points.
संबंधित प्रश्न
Choose the most appropriate answer of the following:
Bonding in this molecule can be understood to involve coordinate bonding
(A) Carbon tetrachloride
(B) Hydrogen
(C) Hydrogen chloride
(D) Ammonium chloride
Identify the anion present in the following compounds:
A salt M on treatment with concentrated sulphuric acid produces a gas which fumes in moist air and gives dense fumes with ammonia
The following table shows the test a student performed on four different aqueous solutions which are X, Y, Z and W. Based on the observations provided, identify the cation present:
| Chemical test | Observation | Conclusion |
| To solution X, ammonium hydroxide is added in minimum quantity first and then in excess |
A dirty white precipitate is formed which dissolves in excess to form a clear solution |
(1) |
| To solution Y ammonium hydroxide is added in the minimum quantity first and then in excess |
A pale blue precipitate is formed which dissolves in excess to form a clear inky blue solution. |
(2) |
| To solution W a small quantity of sodium hydroxide solution is added and then in excess. |
A white precipitate is formed which remains insoluble. |
(3) |
| To a salt Z calcium hydroxide the solution is added and then heated. |
A pungent smelling gas turning moist red litmus paper blue is obtained. |
(4) |
Give a reason for Inert gases do not form ions.
Why do atoms combine?
Fill in the blank
Coordinate bond is also called __________bond.
Draw an electron dot diagram of a hydronium ion and label the lone pair of electrons.
By drawing an electron dot diagram, show the lone pair effect leading to the formation of the ammonium ion from ammonia gas and hydrogen ion.
Give suitable chemical terms for the bond formed by a shared pair of electrons with both electrons coming from the same atom.
Bonding in this molecule can be understood to involve coordinate bonding.
