Select all cases where the substance shown has a molecular dipole.
CH4 methane
CH3CH2CH2CH3 butane
ICl iodine chloride
H2Se hydrogen selenide
CH3CHO acetaldehyde
CH3OCH2CH3 methylethylether
None
To determine if/not dipole, you need two pieces of information.
1. Does the central atom and the atoms attached have a difference in electronegativity? If no, definitely not. If yes, it MAY (or may not) have a dipole moment for the molecule.
2. Is the molecule symmetrical in three dimensions. If symmetrical, no dipole; if unsymmetrical, yes a dipole moment for the molecule.
CH4. Is symmetrical. No dipole moment.
Butane. symmetrical. no dipole moment for the molecule.
ICl. Difference in EN. Must be polar. Must have be a dipole.
H2Se. Difference in EN. Molecule in not symmetrical. Has a dipole moment.
I'll leave the other for you.
To determine which substances have a molecular dipole, we need to examine the molecular structure of each substance and identify any polar bonds.
A molecular dipole occurs in a molecule when there is an uneven distribution of electron density, resulting in partially positive and partially negative charges on different ends of the molecule.
Let's examine each substance:
1. CH4 (methane): In methane, the carbon atom is bonded to four hydrogen atoms. Since carbon and hydrogen have similar electronegativities, the shared electrons are evenly distributed, resulting in a nonpolar bond. Therefore, CH4 does not have a molecular dipole.
2. CH3CH2CH2CH3 (butane): Similar to methane, butane consists of carbon and hydrogen atoms. Since the carbon-hydrogen bonds are nonpolar, there are no molecular dipoles present in butane.
3. ICl (iodine chloride): Iodine chloride consists of an iodine atom bonded to a chlorine atom. Both iodine and chlorine have different electronegativities, resulting in an uneven distribution of electron density. Therefore, the I-Cl bond in ICl is polar, and the substance has a molecular dipole.
4. H2Se (hydrogen selenide): Hydrogen selenide consists of a hydrogen atom bonded to a selenium atom. Selenium has a higher electronegativity than hydrogen, creating a polar bond. Hence, H2Se has a molecular dipole.
5. CH3CHO (acetaldehyde): Acetaldehyde consists of a carbon atom bonded to three hydrogen atoms and a carbonyl group (C=O). The carbon-oxygen bond in the carbonyl group is polar due to the difference in electronegativity between carbon and oxygen. Therefore, CH3CHO has a molecular dipole.
6. CH3OCH2CH3 (methylethylether): Methylethylether consists of a carbon atom bonded to three hydrogen atoms and an ethyl group (CH2CH3). The carbon-oxygen bond in the molecule is polar due to the difference in electronegativity between carbon and oxygen. Thus, CH3OCH2CH3 has a molecular dipole.
Based on this analysis, the substances ICl, H2Se, CH3CHO, and CH3OCH2CH3 have molecular dipoles.