Question

Chile saltpeter is the nitrate mineral of:
(A) potassium
(B) sodium
(C) calcium
(D) lithium

Answer 1

Hint: Chile saltpetre is a combustible salt, capable of being used as an explosive. It was used extensively as a fertilizer and a raw material for manufacture of gunpowder in the late 19th century.

Complete answer
 (1) Chile saltpeter is also known as alkali metal nitrate salt.
(2) It is mainly found in Chile.
(3) The chemical formula is $NaN{O_3}.$
(4) Its appearance is white powder or colorless crystals.
(5) The three naturally occurring nitrates are (a) Ordinary saltpeter (b) Chile saltpeter (c) Lime saltpeter.
(6) These three nitrates generally occur as efflorescence is caused by oxidation of nitrogenous matter in presence of the alkalis.
(7) It is soluble in water, alcohol and liquid ammonia.
(8) It is also used for tree stump removal, racket propellants and fireworks.
(9) The molar mass of sodium nitrate is $84.9947g/mol.$
(10) The melting point is ${308^\circ }C.$
(11) This compound is also found as preservative for.example: park, fish etc.

Therefore, from the above explanation, the correct answer is, option (B) Sodium

Note:
Nitrates can be grouped as minerals of the form $A(N{O_3})$.
Sodium nitrate or Chile saltpeter is used as oxidizer in fireworks. Sodium nitrate, together with potassium nitrate and calcium nitrate is also used for heat transfer in solar power plants.