Question

What is the difference between "intramolecular forces" and "intermolecular forces"? Be sure you explain and contrast the general meanings, rather than giving specific examples of them. Limit your answer to two sentences maximum. Then choose the correct answer for each of the following parts:

Which one of these is most relevant for the process of dissolving, leading to different solubility properties of various neutral covalent compounds in various solvents?

Which one of these is most relevant for the process of melting, leading to different literature melting points of various pure neutral covalent compounds?

A student performs this experiment but does not have the flask boiling when dissolving the original sample. All other steps are performed correctly (using the minimum amount of solvent to dissolve as much of the sample as possible, etc.). What will be the effect on this student’s eventual percent recovery after recrystallization as a result of this mistake? Explain in one sentence.

A student performs this experiment but forgets to rinse the product after vacuum filtration. Which type(s) of impurity would likely be present the following week? Choose among: “soluble”, “insoluble”, “both”, or “neither”, and explain in one sentence.

Consider the following solubility data for a certain compound in water:

Temperature (°C)	Solubility (g/L)
100	56.3
25	3.44
0	1.70

What is the minimum amount of boiling water (in mL) required to fully dissolve 1.00 g of this compound?

A student dissolves 1.00 g of this compound in 50 mL of boiling water, cools to room temperature (25 °C), and collects the crystals by vacuum filtration. What is the theoretical maximum percent recovery this student could possibly achieve?

A student dissolves 1.00 g of this compound in 50 mL of boiling water, cools in an ice bath (0 °C), and collects the crystals by vacuum filtration. What is the theoretical maximum percent recovery this student could possibly achieve?

Answer 1

1) Intermolecular force is between different molecules whereas intramolecular force is within a single molecule.

2) Intermolecular forces hold molecules together in a solid or liquid whereas intramolecular forces are the bonding of atoms that holds a molecules together.Intermolecular forces hold molecules together to form solids and liquids whereas intramolecular forces hold atoms together to form molecules.

Let us take water(H₂O) as an example -----

Intermolecular forces

So called hydrogen bonding. The difference between the electronegativity between hydrogen and oxygen creates a positive charge on hydrogen and a negative charge on oxygen. The negative charge attracts the hydrogen on a neighboring molecule. This helps to hold the water molecules together.

Intramolecular forces
The bonds between hydrogen and oxygen hold the water molecule together. The sharing of electron density creates a bond that holds the two atoms together.

Types of intermolecular forces of attraction that exist between molecules are--- dipole-dipole interactions,hydrogen bonding ,london dispersion forces.

Types of intramolecular forces of attraction that exist between molecules are---ionic bond ,covalent bond,metallic bond.