Water is a polar solvent, meaning it has partial positive and negative charges due to the difference in electronegativity between hydrogen and oxygen atoms. Polar solvents like water are effective at dissolving other polar substances or substances capable of hydrogen bonding. Let's analyze each of the given options to determine whether it is polar or nonpolar:
a) Salt (NaCl):
Salt is an ionic compound composed of positively charged sodium ions (Na[tex]\(^+\)[/tex]) and negatively charged chloride ions (Cl[tex]\(^-\)[/tex]). Ionic compounds are highly soluble in polar solvents like water because the positive and negative ions can interact with the partial charges of the water molecules.
b) [tex]\(CH_3-COOH\)[/tex] (Acetic acid):
Acetic acid has a polar carboxyl group (COOH), which can form hydrogen bonds with water. This makes acetic acid highly soluble in water.
c) [tex]\(CH_3-CH_2-OH\)[/tex] (Ethanol):
Ethanol has a hydroxyl group (OH), which is polar and capable of forming hydrogen bonds with water molecules. This means ethanol is very soluble in water.
d) Sugar (e.g., glucose):
Sugar molecules have multiple hydroxyl groups (OH), which are polar and can form hydrogen bonds with water. This makes sugars highly soluble in water.
e) [tex]\(CH_3-CH_2-CH_2-CH_3\)[/tex] (Butane):
Butane is a hydrocarbon with only carbon-carbon and carbon-hydrogen bonds, which are nonpolar. Nonpolar molecules do not dissolve well in polar solvents like water because they cannot interact with the water molecules via hydrogen bonding or dipole interactions.
Hence, out of the given options, butane ([tex]\(CH_3-CH_2-CH_2-CH_3\)[/tex]) is the substance that will not dissolve in water. Thus, the correct answer is:
e) [tex]\(CH_3-CH_2-CH_2-CH_3\)[/tex]
