Is CH4O a polar molecule? does it have a dipole moment?
The correct answer and explanation is:
Correct Answer: Yes, CH₄O (methanol) is a polar molecule and has a dipole moment.
Explanation:
CH₄O is the molecular formula for methanol, which has the structural formula CH₃OH. This molecule consists of a methyl group (CH₃−) attached to a hydroxyl group (−OH). To determine if a molecule is polar, it is necessary to consider two main factors: the difference in electronegativity between atoms and the geometry of the molecule.
In methanol, the oxygen atom is significantly more electronegative than both carbon and hydrogen. This means oxygen pulls the shared electrons in its bonds more strongly toward itself. The O−H bond is particularly polar because of the large electronegativity difference between oxygen and hydrogen. The C−O bond is also polar due to the difference in electronegativity between carbon and oxygen.
Although the CH₃ group is relatively nonpolar, the presence of the polar OH group creates an uneven distribution of electron density across the molecule. This results in a net dipole moment that points from the hydrogen of the OH group toward the oxygen atom. The molecular geometry of methanol supports this because the molecule is not symmetrical enough to cancel out the dipole.
Methanol has a bent geometry around the oxygen atom due to its two lone pairs of electrons, similar to the shape of water. This bent shape helps reinforce the separation of charge, making the molecule permanently polar.
Since there is a net separation of positive and negative charges and the bond dipoles do not cancel, methanol clearly has a measurable dipole moment. This polarity gives methanol several important properties, such as being highly soluble in water and having hydrogen bonding capabilities.