Question

Is it possible for the dispersion forces in a particular substance to be stronger than hydrogen bonding forces in another substance? Explain your answer.

Short answer

Yes, dispersion forces can be stronger than hydrogen bonding.

Step-by-step solution

Explanation 

Dispersion forces comes to play when there are non-polar molecules whereas hydrogen bonding, occurs in between electro negative elements. Generally, dispersion forces are the weakest forces but in some cases it become stronger.

Let us consider some large molecules, like water and iodine at room temperature. Water molecules act as an electro negative element, contains hydrogen bonding between the hydrogen and oxygen atoms. Whereas iodine contain dispersion forces as iodine molecule is non-polar in nature. Now it can be stated that, water is present in liquid state at room temperature, whereas iodine is present in solid state. As we know, inter molecular forces of attraction are more in solid and also the melting point of water at room temperature is 0°C whereas in iodine it is 113.7°C. So, we can conclude that when the molecules or the atoms in the molecule is large enough then the dispersion forces can become stronger than the hydrogen bonding, such as in the case of iodine and water.