01 Feb

Displacement Reaction In The Periodic Table

Chemistry tuition classes in Miracle Learning Centre is easy to understand and help you in the chemistry tuition application questions. If you do not understand chemistry in school, you must definitely come for chemistry tuition classes at Miracle Learning Centre. Let us learn about displacement reactions in the chapter called “Periodic Table” in this chemistry tuition lesson.
Group VII elements in the periodic table undergo displacement reaction. This is because group VII elements consists of fluorine being the most reactive halogen. Reactivity of halogen decreases down the group, hence fluorine is the most reactive, followed by chlorine, bromine and iodine.
Potassium iodide undergoes a displacement reaction when chlorine is added to it. As a result, potassium chloride and iodine is formed. The colorless solution turns brown. Chlorine can displace iodine from potassium iodide because chlorine is more reactive than iodine and hence chlorine can displace iodide ions from a solution of potassium iodide. On the other hand, potassium chloride does not react with iodine. This is because iodine is less reactive than chlorine, hence iodine cannot displace chloride ions from a solution of its salt. This displacement reaction is a redox reaction. You can see from when potassium iodide reacts to form iodine, the oxidation state of iodide ions increases from minus one to zero in iodine, hence potassium iodide has been oxidised. Chlorine has been reduced, as its oxidation state decreases from zero in chlorine to minus one in potassium chloride. Since oxidation and reduction has taken place, a redox reaction has taken place.
The student from Miracle Learning Centre asks, “Why do we need to learn about displacement reaction?” Mrs Lew from Miracle Learning Centre replied, “We are able to tell from the displacement reaction which halogen is a more reactive halogen. For example, we can tell that the fluorine is more reactive than chlorine, followed by bromine and followed by iodine from the results of the displacement reaction. From the displacement reaction, we are also able to tell that fluorine is the strongest oxidising agent followed by chlorine, bromine and iodine.
Finally, the strongest reducing agent would be the more reactive metal. Hence comparatively, we can tell that potassium is a stronger reducing agent compared to sodium and lithium. Since reactivity in Group I increases down the group, the most reactive metal in Group I is francium followed by caesium, rubidium, potassium, sodium and lithium. Group I metals react with water to form metal hydroxide and hydrogen gas. For example, sodium reacts with water to form sodium hydroxide and hydrogen. The reaction of rubidium with water is much faster than sodium with water since reactivity increases down the group. Hence if you know that rubidium is going to react with water in the laboratory, please make sure you stand far away and there is a protective shield so that you will not be injured.”

Miracle Learning Centre aims to educate students about displacement reaction in the periodic table. Do come to Miracle Learning Centre for more chemistry tuition lessons to learn more about displacement reaction in the periodic table.

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