`=>` Potassium chlorate, when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of `653-873K.`
`2KClO_3 → 2KCl +3O_2`
`=>` However, when a little of manganese dioxide is added, the decomposition takes place at a considerably lower temperature range, i.e., `473-633K` and also at a much accelerated rate.
`=>` The added manganese dioxide remains unchanged with respect to its mass and composition.
`=>` In the same way, the rates of a number of chemical reactions can be altered by the mere presence of a foreign substance.
`=>` The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius, in 1835. He suggested the term catalyst for such substances.
`color{purple}(✓✓)color{purple} " DEFINITION ALERT"`
`text(Definition :)` Substances, which alter the rate of a chemical reaction and themselves remain chemically and quantitatively unchanged after the reaction, are known as catalysts, and the phenomenon is known as catalysis.
`text(Promoters and Poisons :)` Promoters are substances that enhance the activity of a catalyst while poisons decrease the activity of a catalyst.
`text(Example :)` In Haber’s process for manufacture of ammonia, molybdenum acts as a promoter for iron which is used as a catalyst.
`N_2 (g) +3H_2 (g) underset(Mo(s)) overset(Fe(s))→ 2NH_3 (g)`.
`=>` Potassium chlorate, when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of `653-873K.`
`2KClO_3 → 2KCl +3O_2`
`=>` However, when a little of manganese dioxide is added, the decomposition takes place at a considerably lower temperature range, i.e., `473-633K` and also at a much accelerated rate.
`=>` The added manganese dioxide remains unchanged with respect to its mass and composition.
`=>` In the same way, the rates of a number of chemical reactions can be altered by the mere presence of a foreign substance.
`=>` The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius, in 1835. He suggested the term catalyst for such substances.
`color{purple}(✓✓)color{purple} " DEFINITION ALERT"`
`text(Definition :)` Substances, which alter the rate of a chemical reaction and themselves remain chemically and quantitatively unchanged after the reaction, are known as catalysts, and the phenomenon is known as catalysis.
`text(Promoters and Poisons :)` Promoters are substances that enhance the activity of a catalyst while poisons decrease the activity of a catalyst.
`text(Example :)` In Haber’s process for manufacture of ammonia, molybdenum acts as a promoter for iron which is used as a catalyst.
`N_2 (g) +3H_2 (g) underset(Mo(s)) overset(Fe(s))→ 2NH_3 (g)`.