Question

show me the work in a clear hand writing so i can understand please

Shape, melting point & solubility (2.5 pts) When melting or boiling a substance (both of which are physical changes), which kinds of attractions may be broken? Circle all that apply. hydrogen bonding covalent bonds dipole-dipole London forces If I told you that only one of these molecules is a solid at room temperature, which one is that more likely to be? How can you tell from the structure? Circle the hydrophilic portion of the molecules above and put a box around the hydrophobic parts. Are these molecules likely to dissolve in water? How have you decided?

Answer 1

When a substance is either melted or boiled, the attraction that might break are hydrogen bonds, dipole-dipole interactions and london dispersion forces. These are weak forces and easily break by supplying little heat energy.

However covalent bonds are strong chemical bonds that do not easily break. Thus, when a substance is either melted or boiled, covalent bonds will not break.

Unsaturated fatty acids are liquid at room temperature. The structure on left is unsaturated fatty acid. It is a liquid at room temperature. It contains $C=C$ double bond in the hydrocarbon part.

Saturated fatty acids are solid at room temperature. The structure on right is saturated fatty acid. It is a solid at room temperature. It does not contains $C=C$ double bond in the hydrocarbon part.

OH oleic acid Unsaturated, liquid OH stearic acid Saturated, solid O

Hydrophilic parts are circled and hydrophobic parts are boxed as shown below.

"он/ oleic acid Unsaturated, liquid "он stearic acid Saturated, solid O:

Due to presence of large (non polar) hydrocarbon part, these molecules are not likely to dissolve in (poalr) water. This is because like dissolves like.