Question

Assertion
Amalgam of mercury with sodium is an example of solid solutions.
Reason
Mercury is solvent and sodium is solute in the solution.
A ) Both assertion and reason are correct and reason is the correct explanation for Assertion.
B ) Both assertion and reason are correct but reason is not the correct explanation for Assertion.
C ) Assertion is correct but reason is incorrect.
D ) Both assertion and reason are incorrect.

Answer 1

Mixture of two or metals with mercury is known as amalgam. Amalgam is a solid solution in which solute is a liquid and solvent is a solid.

Complete answer:
Several metals form amalgams with mercury metal. Amalgams are alloys of mercury with other metals. Certain intermetallic compounds are also the amalgams.
Certain solid solutions and liquid solutions can be called amalgams if they involve mercury as main constituents. Thus, in amalgams, mercury metal is in excess.
When alloy of mercury metal and sodium metal is formed, with an amount of mercury being smaller than that of sodium, the amalgam is called sodium amalgam. Sodium amalgam is a strong reducing agent. Sodium is highly electropositive metal. Hence, it acts as a reducing agent. But sodium metal needs better handling properties as it has high reactivity with moisture. Hence, instead of using pure sodium metal, its amalgam is used.
Amalgam of mercury with sodium is an example of solid solutions. It contains a liquid solute and solid solvent. Hence, the assertion is correct.
Since, the amount of mercury is smaller than that of sodium, mercury is a solute and sodium is a solvent. Hence, the reason is incorrect

Hence, the correct option is the option C ) Assertion is correct but reason is incorrect.

Note: A binary solution contains two components, a solute (present in small amount) and solvent (present in large amount). Based on the physical state of solute and solvent (solid liquid or gas) solutions are classified into nine categories. Solid solution is one such category.