What substance will have the lowest surface tension?
A) HOCH2CH2OH
B) CH2F2
C) CH3CH2F
D) CH3CH2OH
E) CH3CH2CH CH3CH3
Je ne sais pas mais je pence que cest A
To determine which substance will have the lowest surface tension, we need to consider the molecular structure and polarity of each substance. The surface tension of a liquid depends on the strength of the forces between its molecules.
Surface tension is generally lower for substances with lower intermolecular forces or weaker molecular interactions. Substances with polar molecules typically have stronger intermolecular forces, resulting in higher surface tension.
Let's analyze each substance:
A) HOCH2CH2OH (ethanol): Ethanol is a polar molecule due to the presence of the hydroxyl group (OH). It can form hydrogen bonds, which are strong intermolecular forces. This contributes to higher surface tension.
B) CH2F2 (difluoromethane): Difluoromethane is a nonpolar molecule because the fluorine atoms exert equal and opposite electron-pulling forces on the central carbon atom. Nonpolar substances typically have weaker intermolecular forces, resulting in lower surface tension.
C) CH3CH2F (ethyl fluoride): Ethyl fluoride is a polar molecule due to the presence of the fluorine atom. It can form dipole-dipole interactions, which are relatively strong intermolecular forces. This contributes to higher surface tension compared to nonpolar substances.
D) CH3CH2OH (ethanol): Similar to (A), ethanol is a polar molecule with strong intermolecular forces (hydrogen bonding). Thus, it will have higher surface tension.
E) CH3CH2CH2CH3 (butane): Butane is a nonpolar molecule because it consists of only carbon and hydrogen atoms. Nonpolar substances typically have weaker intermolecular forces and thus lower surface tension.
Comparing these substances, we can see that B) CH2F2 (difluoromethane) and E) CH3CH2CH2CH3 (butane) have nonpolar molecules, resulting in weaker intermolecular forces and, therefore, the lowest surface tension.
So, the correct answer is B) CH2F2.