Chemistry- Mg Cl and H Cl?

Question

Magnesium chloride and hydrogen chloride are two compounds of chlorine.At room condition,magnesium chloride exists as a solid but hydrogen chloride exists as gas.Why?

Answer 1

First of all, magnesium chloride is MgCl2 and its bonds are not all that ionic.  MgCl2 is a solid not so much that the bonds have slightly more ionic character, but that the atoms form a regular network, so that every atom is part of a giant lattice.

Image of the network arrangement of Mg and Cl, which is the same as the arrangement of Cd and Cl.

http://upload.wikimedia.org/wikipedia/en...

The Mg-Cl bond, with an electronegativity difference, of 1.85 is 57 percent ionic (or 43 percent covalent).

The bond in HCl, with an electronegativity difference of 0.95, is 21 percent ionic (or 79 percent covalent).  But more importantly, there is no regular arrangement of H and Cl atoms in a network.  Therefore HCl exits as discrete molecules whereas MgCl2 does not.  MgCl2 exists as a network, which gives it its higher melting point.

Answer 2

why?

that is a very difficult question...

its is becasue it is their nature...

like water is liquid and air is gas!!!!

and i think HCl is liquid

Answer 3

because HCl is much of a polar molecule. the bonds holding the molecules to other molecules is not as strong, so they move faster at lower temperatures.

make it a good day

Answer 4

MgCl is an ionic compound, so it is held by very strong electrostatic force.  But HCl is a covalent compound and there is only weak Van Der Walls force among its molecules. For this reason magnesium chloride exists as a solid but hydrogen chloride exists as gas.