Choose the member of each set that you would expect to be more soluble in water. Explain your answer.
Chloroform, CH3Cl, or hydrogen chloride.
My gut instinct was HCl, however I'm not sure why [or if] it's more soluble than CH3Cl.
Of course HCl is more soluble in water than chloroform. HCl is highly polar and the reaction with water is
HCl(g) + H2O ==> H3O^+ + Cl^-
You've seen hydrochloric acid in the lab and read about it in your text so you must know it's soluble. Your gut instinct is good but in most classes that won't get any points unless you can tell WHY.
To explain why hydrogen chloride (HCl) is more soluble in water than chloroform (CH3Cl), we need to consider the intermolecular forces involved.
Water is a polar molecule, meaning it has a partial positive charge on one end (the hydrogen atoms) and a partial negative charge on the other end (the oxygen atom). This polarity allows water molecules to form hydrogen bonds with other polar molecules or ions.
HCl is also a polar molecule, with a partial positive charge on the hydrogen atom and a partial negative charge on the chlorine atom. When HCl is dissolved in water, the partial positive charge of the hydrogen atom can form a hydrogen bond with the partial negative charge of water's oxygen atom. These hydrogen bonds help to stabilize the HCl molecules in the water solution, resulting in high solubility.
On the other hand, chloroform (CH3Cl) is a nonpolar molecule. It does not have significant partial charges on its atoms, and therefore, it cannot form hydrogen bonds with water. The only intermolecular force present in chloroform is London dispersion forces, which are weaker than hydrogen bonds. As a result, the solubility of chloroform in water is relatively lower compared to HCl.
In conclusion, the polar nature and ability to form hydrogen bonds of HCl make it more soluble in water than the nonpolar chloroform.