How can you prove with an example that conversion of an ion to an atom is an oxidation
process?
in an equation form
Answers
Answer:
Answer: Ion loses an electron, it is an oxidation reaction. An element M reacts with another element X to form MX2 In terms of loss or gain of electrons, identify the element which is oxidized and which is reduced M M+2 + 2e— loses two electrons, so it is oxidized.
Chemist use these terms “by extension”. You can learn chemistry, or any subject almost, as just a shallow bunch of rules to get you through an exam, or you can go deeper. I am going to go really deep with this answer, and its a challenging ride, so I hope you can follow along. Even PhDs have to do some mental gymnastics to tie these ideas together, for example cell biologists have to deal with chemical reactions involving electron and proton transport in relation to electrical potentials in ionic environments. It gets tricky.
Hydrogen literally means the water generator, and oxygen literally means the acid generator. This is because if you burn hydrogen you get water, and if you aerate wine you produce vinegar. It seems hard to imagine how these ideas became unified in modern theory. But they did, and even before atomic theory.
Now if we reduce the air to a furnace, then naturally such processes were called reduction. So charcoal for example is a reduction product. Likewise iron metal is produced by reduction of an oxide ore, and so reduction corresponds to a lower oxidation level, or state. Abstract thinking! Cool. A theory is emerging.
From this we can reason that if wine is oxidised into acetic acid, then there is a correspondance here, we could say that alcohol is the reduced form of an acid. The lexicon is all revolving around generalising the nature of oxygen. Much of this thinking can be traced back to Lavoisier.
By extension, wr arrive at the concept of oxidation state for metals, a concept that is transferable for the behaviour of metals when in compound or in solution. Iron chlorides for example are analogous to iron oxides, we can recognise homologies. This allowed the development of the concept of reactivity, using oxygen as the reference state. All this happened before atomic theory developed, but you can clearly see that atomic theory already had a solid experimental grounding.
Once the organic chemists began investigating biologically derived materials, it turned out that the loss of oxygen in organics corresponded also to a gain in hydrogen content. By displacing oxygen and completely maximising hydrogen, this kind of reductive process eventually saturated organics with hydrogen. A saturated fat means that, you have added in as much hydrogen as it can take, and reduced the oxygenated form to hydroxyl C-OH, or even more, to C-H.
Davy and Faraday were expert electrochemists, and they were able to apply the oxidation and reduction concepts to metallic states, and the vision of “atoms of electricity” began to materialise. Oxidations were eventually identified with loss of electrons. I learnt this as a student by reminding myself that Oxidation is the lOss of electrons. The tie back to oxygen is because oxygen molecules share electrons with themselves in an inefficient manner, and when they react in combustions and oxidations they split, and each takes in more negative charge. We say that oxygen atoms are electrophilic. The periodic table really helps in generalising these concepts, chlorine and phosphorous and these atoms are also electrophilic. Reactive non metals are usually oxidising agents, all because historically oxygen is the prototype.
Now when you electrolyse water, you find oxygen produced at one electrode, and hydrogen at the other. This closes the deal. The reactions can be split clearly into pairs, or poles. One half-reaction is the oxidation partner, the other is the reduction partner. Together it becones a redox couple.
If copper metal is produced at one electrode, then we would also expect that it would be the same one that would remove oxygen from water. Reduction. And indeed this is observed.
Let's consider electrolysis of copper chloride. If one electrode becomes plated in copper, then the oxidation state of copper has reduced to the metallic state. Reduction of cupric to cuprous to elemental state. It gained electrons. Conversely sonething must get oxidised at the other electrode. Chlorine that originally “combusted” to form chloride in the salt will be regenerated and released as elemental chlorine. Chloride anions lose electrons.
So now where would hydrogen gas be expected? Well at the reducing electrode. Hydrogen ions, protons in fact, are behaving just as we expect, like metal ions. That is why we put it in the first column. Instead if a reduced metal plating out we get reduced hydrogen gas forming. And we can still talk about hydrogen gas as a reducing agent if we use it in a subsequent industrial process such as the hydrogenation of margarine. If we leave the marge, or butter, out of the fridge too long the oxidation in air proceeds more rapidly and oxygen produced smelly acids like butyric acid. Oxygen, the acid maker. Or the fats under your armpit will oxidise to make even smellier acids. The longer the carbon chain, the smellier the acid. :)