Question

The phlogiston theory was suggested for _______________ reaction.
A.Neutralization
B.Oxidation
C.Reduction
D.Combustion

Answer 1

Hint: The word phlogiston comes from the ancient Greek word ‘phlogistón’ which means ‘burning up’ from the word ‘phlóx’ or ‘flame’ in Greek.

Complete step by step answer:
The phlogiston theory postulated that there fire-like elements called ‘phlogiston’ present in substances that are combustible and these bodies are released during combustion. This theory was initially proposed by Joahnn Joachim Becher but was put in a more descriptive manner by Georg Ernst Stahl.
According to the theory, phlogisticated substances contain phlogiston which are released while burning or combustion and thereafter the bodies become dephlogisticated. This theory was put forward initially to explain the phenomenon of combustion and rusting which is collectively known as ‘oxidation’ now.
This theory was completely abandoned after the discovery of oxygen by Antoine Lavoisier and others. Lavoisier proved that combustion requires oxygen, which is a gas having mass that can be weighed, and from then the phlogiston theory got rejected.

Note:
Joahnn Joachim Becher was the first person to conceive the idea of phlogiston and he proposed that there are three types of earthly materials. One is “vitrifiable”, another is “mercurial”, and lastly the “combustible” or terra lapidea, terra fluida, and terra pinguis. He believed that terra pinguis was released when combustible substances were burned.
Georg Ernst Stahl applied the name ‘phlogiston’ to the theory of Becher. Stahl believed that corrosion is also a form of combustion and that when metals are converted to their metallic ash, then phlogiston are released leading to the metals getting dephlogisticated.