If a dried aspirin sample is contaminated with a trace amoun

If a dried aspirin sample is contaminated with a trace amount of acetaminophen, what effect could this have on the observed melting point?

Solution

Melting point (m.p.) will provide us information about how much pure our sample is.

Compounds in pure solid form are generally arranged in a tightly packed repeating crystal lattice. These lattices are held together by intermolecular forces. When we will give energy, these forces will be disturbed and substances will melt.

When a pure compound contains some impurity, the intramolecular forces between pure compound will be disturbed and in turn, will become weak which require a lower amount of energy to break. This explains the lowering of Melting point for impure solids.

Thus In case of Aspirin sample is contaminated with a trace amount of acetaminophen will lower its melting point due to above reason.