Question

Sodium amalgam is a mixture of sodium and
A. Mercury
B. bromine
C. tin
D. iron

Answer 1

Sodium amalgam is a type of alloy which consists of two materials. The sodium amalgam is made up of sodium and element which has the atomic number of 80. It is used as a reducing agent in many organic reactions.

Complete answer:
- In the given question, we have to identify the element other than the sodium present in a mixture of sodium amalgam.
- As we know it is an alloy i.e. the mixture of two metals and also the atomic number of the element is 80 so, according to the periodic table the element is mercury.
- So, sodium amalgam is a mixture of two metals that are sodium and chief element mercury and have a molecular formula of $\text{Na-Hg}$.
- For the preparation of the sodium amalgam, sodium metal is dissolved in the mercury and there is a release of the heat in the process.
- It can also be produced by the chloralkali process, in which the electrolysis of sodium chloride takes place and sodium amalgam is formed as a by-product.
- That's why the process of the sodium amalgam formation is exothermic.
- Sodium amalgam is used in the reaction as a reducing agent as it can reduce the molecule by the removal of oxygen and the addition of the hydrogen atom.

Therefore, option A is the correct answer.

Note: There are many types of amalgam in which the mercury and other elements are present such as zinc amalgam, potassium amalgam, aluminium amalgam, etc. An amalgam also has a restorative property due to which it is widely used by the dentists to treat the teeth related problems.