Question

Melting point of phenol is:
A) ${{53} ^ {\circ}} C$
B) ${{43} ^ {\circ}} C$
C) ${{33} ^ {\circ}} C$
D) ${{23} ^ {\circ}} C$

Answer 1

Hint: The melting point of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa.

Complete step by step answer:
We have been provided with phenol,
Phenol is an aromatic organic compound with the molecular formula ${{C}_ {6}} {{H}_ {5}} OH$. It is a white crystalline solid that is volatile. The molecule consists of a phenyl group bonded to a hydroxyl group. Mildly acidic, it requires careful handling because it can cause chemical burns.

We need to determine its melting point,
The melting point is usually defined as the point at which materials change from a solid to a liquid. The temperature at which solid changes its state to liquid at atmospheric pressure is called the melting point of that liquid. This is the point at which both liquid and solid phases exist at equilibrium.
Phenol is a crystalline solid and it has a definite melting point: ${{43} ^ {\circ}} C$.
So, we can say that the melting point of phenol is ${{43} ^ {\circ}} C$.
Therefore, option (b) is correct.

Note: Phenols are widely used in household products and as intermediates for industrial synthesis. For example, phenol itself is used (in low concentrations) as a disinfectant in household cleaners and in mouthwash. Phenol may have been the first surgical antiseptic.