Question

Which of the compounds, c3h8, mgcl2, zn(no3)2, ocl2, are expected to exist as molecules?

Answer 1

Explanation:

A molecular compound is a compound in which atoms share electrons with each other and thus, forms covalent bonds. As a result, molecular compounds are covalent compounds.

In the compound $C_{3}H_{8}$, since hydrogen atom has only one electron and carbon atom has 4 electrons in its valence shell. So, in order to completely fill its octet both carbon and hydrogen will share electrons with each other.

Therefore, $C_{3}H_{8}$ is a covalent compound. Hence, it is also a molecular compound.

In $MgCl_{2}$, magnesium being a metal has excess of electrons and chlorine being a non-metal has deficiency of electrons. Thus, magnesium donates its two electrons to both the chlorine atoms and forms an ionic bond.

Hence, $MgCl_{2}$ is an ionic compound. Thus, it is not a molecular compound.

In $OCl_{2}$, both oxygen and chlorine are non-metals. Hence, they have deficiency of electrons. As a result, both oxygen and chlorine will share electrons in order to complete their octet.

So, there will be formation of covalent bonds. Thus, $OCl_{2}$ is a molecular compound.

$Zn(NO_{3})_{2}$ is an inorganic compound and dissolves in water to form ions of $Zn^{2+}$ and $NO^{-}_{3}$. Hence, $Zn(NO_{3})_{2}$ is an ionic compound.

Thus, we can conclude that out of the given options, $C_{3}H_{8}$ and $OCl_{2}$ exists as molecules.

Answer 2

The answer is C3H8 and OCl2  they are molecular compounds. MgCl2 is an ionic compound while Zn(NO3)2 is an inorganic chemical compound. 
Molecular compounds are covalent compounds in which the elements share electrons via covalent bonds. They are inorganic compounds that take the form of discrete molecules, for example water and carbon dioxide.