Question

Which of the following is the formula of chile saltpetre?
${\text{A}}{\text{.}}$ ${\text{KN}}{{\text{O}}_3}$
${\text{B}}{\text{.}}$ ${\text{NaN}}{{\text{O}}_3}$
${\text{C}}{\text{.}}$ ${\text{NaN}}{{\text{O}}_2}$
${\text{D}}{\text{.}}$ ${\text{AgN}}{{\text{O}}_3}$

Answer 1

Hint- Here, we will proceed by observing all the chemical formulas of the compounds in the options of the problem. Then, we will discuss all these chemical compounds individually and will see which one of these is having, their other name as chile saltpetre.

Complete answer:

The chemical compound potassium nitrate is a naturally occurring mineral source of nitrogen. It is a nitrate with chemical formula ${\text{KN}}{{\text{O}}_3}$. It is also known as saltpetre, Nitrate of potash and nitre.
Potassium nitrate or saltpetre (${\text{KN}}{{\text{O}}_3}$) is the oxidizing component of black powder. Prior to the large-scale industrial fixation of nitrogen through the Haber process, a major source of Potassium nitrate was the deposits crystallising from cave walls or the draining of decomposing organic material.
Sodium nitrate is the chemical compound with the formula ${\text{NaN}}{{\text{O}}_3}$. This salt is also known as Chile saltpetre. It is different from ordinary saltpetre (potassium nitrate). Sodium nitrate was used extensively as a fertilizer and a raw material for the manufacture of gunpowder.
Sodium nitrate or chile saltpetre is a colourless, odourless, crystalline compound.
Sodium nitrate appears as a white crystalline solid which is non-combustible but accelerates the burning of combustible materials.
Sodium nitrite is the chemical compound with the formula ${\text{NaN}}{{\text{O}}_2}$. This chemical compound is a yellowish or white crystalline compound, soluble in water, slightly soluble in alcohol and ether. It is also used in the manufacture of dyes and as a colour fixative. This compound is also added to food as a preservative and for flavour and colour especially in pork, fish, and beef products.
Silver nitrate is the chemical compound having formula ${\text{AgN}}{{\text{O}}_3}$. It is a colourless crystalline compound which is poisonous in nature. Silver nitrate becomes greyish black in colour when exposed to light in presence of some organic matter. It is also used in the manufacturing process of photographic film. It is also used in various processes like silvering mirrors, dyeing hair and plating silver. Silver nitrate is used in medicine as a cautery and antiseptic.
Therefore, the formula of chile saltpetre is ${\text{NaN}}{{\text{O}}_3}$.
Hence, option A is correct.

Note- If large quantities of chile saltpetre are involved in fire or the combustible material is finely divided an explosion may result. May explode under prolonged exposure to heat or fire. Toxic oxides of nitrogen are produced in fires. Used in solid propellants, explosives, fertilizers, and for many other uses.