Question

What is the formula of sodium hypophosphite
A. $Na{H_2}P{O_2}$
B. $N{a_2}HP{O_3}$
C. $N{a_3}P{O_3}$
D. $Na{H_2}P{O_3}$

Answer 1

The sodium salt of hypophosphorous acid, sodium hypophosphite, is commonly found as the monohydrate, $NaP{O_2}{H_2} \cdot {H_2}O$ . At room temperature, it is a solid that appears as odourless white crystals. It is water soluble and readily absorbs moisture from the environment.

Complete answer:
Sodium hypophosphite, also known as $NaP{O_2}{H_2} \cdot {H_2}O$ , is the sodium salt of hypophosphorous acid. It appears as odourless white crystals at room temperature. It absorbs moisture from the air and is soluble in water.
An aqueous mixture of calcium hydroxide and sodium carbonate is treated with free phosphorus and heated at a temperature between about $70$ and $100{\text{ }}C$ . for a number of hours to create an aqueous solution of sodium hypophosphite, according to a method for making sodium hypophosphite.
Uses:
Electroless nickel plating is the most popular application for sodium hypophosphite $\left( {Ni - P} \right)$ . A robust nickel-phosphorus film can be coated on objects with irregular surfaces using this form, which is useful in avionics, aviation, and the petroleum industry.
On both metal and plastic substrates, sodium hypophosphite is capable of converting nickel ions in solution to metallic nickel. The above necessitates the activation of the substrate with fine palladium particles. The nickel deposit that results contains up to 15% phosphorus.
It has the potential to be used as a food additive.
So, the correct option is: A.$Na{H_2}P{O_2}$

Note:
Sodium hypophosphite should be stored away from oxidising materials in a cold, dry spot. It decomposes into phosphine and disodium phosphate, both of which are irritating to the respiratory tract.
$2{\text{ }}Na{H_2}P{O_2}\; \to {\text{ }}P{H_3}\; + {\text{ }}N{a_2}HP{O_4}$