Question

$C{l_2}O$ is a yellowish-red gas at room temperature. The strongest intermolecular force present in $C{l_2}O$ are:
A. dipole- dipole forces
B. London force
C. Hydrogen bond
D. covalent bond

Answer 1

To hold the atoms or molecules in a compound, certain forces are needed which are generally forces of attractions. Due to these forces different types of chemical bonds are formed which bind the molecule together.

Complete step by step answer:
-dipole- dipole forces – The electron density around an atom is symmetrical in normal situations. When this symmetry fluctuates, it leads to the development of partial charges which leads dipole-dipole interactions. This interaction occurs between the atoms of different electronegativity values. In $C{l_2}O$, the electronegativity of ${\text{Cl is 3}} \cdot {\text{16}}$, and of ${\text{O is 3}} \cdot 44$ . Electronegativity is the tendency to attract a shared pair of electrons toward itself. Since, ${\text{O}}$ is more electronegative than ${\text{Cl}}$, so it will pull the electron cloud of cl towards itself. This leads to the formation of partial charges between the two atoms within the $C{l_2}O$ molecule. This, dipole- dipole forces are present in the $C{l_2}O$. Hence, option (a) is correct.
-London force – is similar to dipole- dipole forces as here also partial charges are formed, but it is not strong the later because here the partial charges formed are temporary. Due to the position of electrons in the atom, a temporary dipole is formed which induces the dipole to another neutral atom near it. Thus, it is called dipole induced dipole force. Hence, option (b) is incorrect.
-Hydrogen bond – It is a special case of dipole-dipole interaction between the molecules. It is a bond formed between a hydrogen atom which is covalently bonded to a very electronegative atom like ${\text{O, N or F}}$, and another a very electronegative atom. Since, $C{l_2}O$ does not involve hydrogen, so, option (c) is incorrect.
-Covalent bond - when electrons are shared between two atoms then the bond formed is called covalent bond. By sharing electrons, atoms gain stability by Octet rule. This bonding is mainly shown by non-metals. Since, here sharing of electrons does not happen in $C{l_2}O$. Hence, option (d) is incorrect.
Hence option (a) is correct as dipole- dipole force is the strongest force in $C{l_2}O$.

Note: In chemistry, a permanent dipole tells about the partial charge separation, and this occurs within a molecule through the bond which forms between two different atoms. It is generally seen between two nonmetals.