Which substance would give a solution with a boiling point below that of pure water rather than above ?

Question

Which substance would give a solution with a boiling point below that of pure water rather than above ? (A) Sodium chloride (solid) (B) Ethyl alcohol (liquid, b.p. 61&deg;C) (C) Sulphuric acid (liquid, b.p. > 300&deg;C) (D) Sucrose sugar (solid)

Tardigrade Admin · Accepted Answer

When two liquids are mixed, the boiling point of the mixture lies somewhere between the boiling points of the two pure substances. Since ethyl alcohol has a lower boiling point than water, a mixture of the two would also have a lower boiling point.

Q. Which substance would give a solution with a boiling point below that of pure water rather than above ?

Sodium chloride (solid)

Ethyl alcohol (liquid, b.p. 61°C)

Sulphuric acid (liquid, b.p. > 300°C)

Sucrose sugar (solid)

When two liquids are mixed, the boiling point of the mixture lies somewhere between the boiling points of the two pure substances. Since ethyl alcohol has a lower boiling point than water, a mixture of the two would also have a lower boiling point.