Question

“When sodium metal is exposed to the atmosphere, it reacts with air and forms sodium hydroxide film which absorbs $C{O_2}$ from air and forms sodium bicarbonate.”
Answer whether the above statement is true or false.
If true, enter 1, else enter 0.

Answer 1

Sodium is ordinarily quite reactive with air. It reacts with water vapour content in the air to give sodium hydroxide film. In ordinary air, sodium metal reacts to form a sodium hydroxide (NaOH) film, which can rapidly absorb carbon dioxide $(C{O_2})$ from the air, forming sodium bicarbonate $(N{a_2}HC{O_3})$ .

Complete step by step answer:
Sodium metal reacts with the oxygen in air to form sodium oxide, and traces of yellowish sodium peroxide.
$4Na(s) + {O_2} \to 2N{a_2}O(s)$
The sodium oxide formed will then react with water vapour in the air to give sodium hydroxide film.
$N{a_2}O + {H_2}O \to 2NaOH$
The sodium hydroxide formed is hygroscopic which means it absorbs moisture from the air. It also absorbs Carbon dioxide from air dioxide to give sodium bicarbonate, which is relatively unreactive to the atmosphere.
$2NaOH(aq) + 2C{O_2}(g) \to 2NaHC{O_3}(aq)$
$C{O_2}$ reacts with aqueous NaOH and forms sodium bicarbonate $\left( {NaHC{O_3}} \right)$ in turn.
So, it is true that when sodium metal is exposed to the atmosphere, it reacts with air and forms sodium hydroxide film which absorbs $C{O_2}$ from air and forms sodium bicarbonate.

Therefore, we enter 1.

Note: Sodium does not react with nitrogen, so we keep sodium usually immersed in a nitrogen atmosphere or in inert liquids such as kerosene or naphtha. Sodium bicarbonate is a white, crystalline powder and is commonly used as a pH buffering agent, an electrolyte replenisher, systemic alkalizer and in topical cleansing solutions. It is slightly alkaline and bitter in taste. It’s pH (of freshly prepared 0.1 molar aqueous solution) is 8.3 at $77^\circ F$ .