Question

a. what is the difference between an intermolecular and intramolecular force?
b. imfs: list the 3 intermolecular and the 2 intramolecular forces from weakest to strongest (there should be 5 in total on 1 spectrum):
c. a covalent molecule with a vapor pressure higher than water is expected to have a boiling point above or below 100°c?
d. polar (sticky)=____=____
nonpolar (not sticky) = ____=____
fill in the 4 blanks above, here’s a word bank (not in any order): asymmetrical, gas, symmetrical, liquid
e. without using google, arrange these 4 compounds from lowest to highest boiling points. hint: assess their polarities and then their masses. explain your decisions:
ethanol c₂h₅oh (a)
ethane c₂h₆ (b)
butane c₄h₁₀ (c)
acetone ch₃coch₃ (d)
f. arrange them in order of lowest to highest vapor pressure. how does this order compare to your response in #5 above?

Explanation:

Step1: Define intermolecular and intramolecular forces

Intermolecular forces are between molecules, like London - dispersion, dipole - dipole, and hydrogen bonding. Intramolecular forces are within a molecule, such as covalent and ionic bonds.

Step2: List forces from weakest to strongest

Weakest to strongest: London - dispersion (intermolecular), dipole - dipole (intermolecular), hydrogen bonding (intermolecular), covalent (intramolecular), ionic (intramolecular).

Step3: Relate vapor pressure and boiling point

Higher vapor pressure means lower boiling point. So a covalent molecule with higher vapor pressure than water has a boiling point below 100°C.

Step4: Fill in blanks

Polar (sticky) = asymmetrical = liquid. Non - polar (not sticky) = symmetrical = gas.

Step5: Arrange boiling points

Ethane (B) has only London - dispersion forces and is smallest. Butane (C) is larger than ethane, also with only London - dispersion forces. Acetone (D) is polar, so has dipole - dipole forces. Ethanol (A) has hydrogen bonding. So order is B < C < D < A.

Step6: Arrange vapor pressures

Vapor pressure is opposite of boiling point. So order is A < D < C < B. The order of vapor pressure is the reverse of the boiling - point order.

Answer:

a. Intermolecular forces are between molecules; intramolecular forces are within a molecule.
b. London - dispersion, dipole - dipole, hydrogen bonding, covalent, ionic.
c. Below 100°C.
d. Polar (sticky)=asymmetrical=liquid; Non - polar (not sticky)=symmetrical=gas.
e. B. Ethane < C. Butane < D. Acetone < A. Ethanol.
f. A. Ethanol < D. Acetone < C. Butane < B. Ethane. The order of vapor pressure is the reverse of the boiling - point order.