identify the intermolecular attractions for dimethyl ether and for ethyl alcohol. which molecule is expected to be more soluble in water? explain
alcohol has a strong hydrogen bond. Ether does not.
To identify the intermolecular attractions for dimethyl ether and ethyl alcohol, we need to consider the types of intermolecular forces or interactions present in each molecule.
Dimethyl ether (CH3OCH3) is a polar molecule due to the electronegativity difference between oxygen and hydrogen atoms, resulting in a partial positive charge on hydrogen and a partial negative charge on oxygen. The intermolecular attractions in dimethyl ether are primarily dipole-dipole interactions.
Ethyl alcohol (C2H5OH) is also a polar molecule, with a hydroxyl group (-OH) that contains an oxygen atom bonded to a hydrogen atom. Ethyl alcohol can form hydrogen bonds due to the presence of the hydrogen bonded to the oxygen atom. In addition to dipole-dipole interactions, hydrogen bonding is a significant intermolecular force in ethyl alcohol.
Comparing the two molecules, ethyl alcohol is expected to be more soluble in water than dimethyl ether. This is because water is a polar molecule, capable of forming hydrogen bonds with other polar molecules. Both dimethyl ether and ethyl alcohol can form dipole-dipole interactions with water molecules. However, ethyl alcohol has the additional ability to form hydrogen bonds with water due to the presence of the hydroxyl group. This strengthens the interactions between ethyl alcohol and water molecules, making it more soluble in water.
To summarize:
- Dimethyl ether exhibits dipole-dipole interactions with water molecules but lacks the ability to form hydrogen bonds.
- Ethyl alcohol exhibits both dipole-dipole interactions and hydrogen bonding with water molecules, making it more soluble in water.
The intermolecular attractions in dimethyl ether and ethyl alcohol are both controlled by van der Waals forces. However, ethyl alcohol also contains an -OH group, leading to additional intermolecular hydrogen bonding.
In comparison, dimethyl ether lacks the -OH group and thus cannot participate in hydrogen bonding. Therefore, ethyl alcohol is expected to be more soluble in water because the presence of hydrogen bonding allows for stronger interactions between the alcohol molecules and water molecules.
Hydrogen bonding occurs when the electronegative oxygen atom in the ethyl alcohol molecule attracts hydrogen atoms from surrounding water molecules. This interaction is relatively strong and can stabilize the alcohol-water mixture, leading to increased solubility.
On the other hand, dimethyl ether lacks hydrogen bonding capability and can only rely on weaker van der Waals forces. Consequently, the intermolecular attractions between dimethyl ether and water are relatively weak, resulting in lower solubility in water compared to ethyl alcohol.