chemical reactivity

Metals are substances that have high electrical conductivity, high thermal conductivity, and high density, to name a few characteristics. Most of the time, they are malleable and ductile, meaning that they deform under stress without cleaving. Metals have a glossy sheen and are highly reflective of optical characteristics. The focus of this article is on the reactivity series of metallic elements.

Metals are often prone to forming cations due to electron loss, which reacts with oxygen in the air to generate oxides across a wide range of reactions.

A passive layer of oxide forms on the surface of transition metals (such as iron, copper, zinc, and nickel), preventing the metal’s core from being oxidized as quickly as it would otherwise. Others, such as palladium, platinum, and gold, do not react with the surrounding environment at all.

Reactivity of metals

An experiment, structural progression, and logical progression of a series of metals in order of reactivity from greatest to lowest reactivity are known as a Reactivity Series in chemistry. Various compounds have different reactions with different metals. It describes in detail metal reactions that occur during the extraction of metals from ores and when metals react with acids and water. In other words, as illustrated in the reactivity series chart below, the most reactive metal is displayed at the top of the chart, and the least reactive metal is provided at the bottom.

All metals have a propensity to lose electrons and generate metal ions when exposed to high temperatures. To put it another way, all metals are excellent reducing agents and are quickly oxidized by themselves.

M → M⁺n + ne⁻

Another technique to depict the reactivity series of metals is to include the oxidation reaction of each metal to the corresponding metal ion in each metal’s series. It provides information on the reducing power of the metal atom as well as the oxidation number of the metal ion in the metal atom.

Prior to examining the reactivity order of metals, it is necessary to understand the distinctions between metals and non-metals in terms of their reactivity.

Reactivity Series of Metals:

The reactivity of metals rises as we go up the reactivity scale from the bottom to the top of the scale. Metals present near the top of the series have a greater tendency to lose electrons, resulting in the formation of positive ions and the corrosion or tarnish of metals. As a result of the increased energy required to extract them from their ore, they become stronger reducing agents, while metals found at the bottom of the series are excellent oxidizing agents.

The metals with a high reactive series, as shown in the preceding table, also imply that reverse reaction is a difficult process to complete successfully. In the case of highly reactive metals, the majority of the reactions are exothermic.

• When it comes to highly reactive metals, the reaction happens quickly
• The electrolysis procedure is used to remove the metals that are present above the carbon layer in the rock
• Carbon and hydrogen play an important and necessary part in the extraction of metals using a process that incorporates carbon and hydrogen

Reactions involving water and acids include the following:

Sodium is one of the most reactive metals known. When it comes into contact with cold water, it creates hydrogen and metal hydroxide.

The reaction 2 Na (s) + 2 H₂O (l) →  2 NaOH (aq) + H₂ (g)

A reaction between sulfuric acid and iron sulfate, which is found in the center of the table of the reactive series, results in the production of hydrogen and a metal salt, iron sulfate.

The Significance of the Reactivity Series

It is possible to forecast the products of displacement reactions by utilizing the reactivity series of metals as a guide. Each element in the reactivity series may be substituted from a compound by any of the components above it in the reactivity series. For example, magnesium metal may cause zinc ions in a solution to displace one another.

Mg (s) + Zn²⁺ (aq)    →  Zn (s) +  Mg²⁺ (aq)

is a chemical reaction. Similarly, the gap between metals in the reactivity series of metals denotes the reactivity of those metals towards one another, and vice versa. When the time separation between elements is longer, the elements will respond more aggressively to one another. In addition, the top five elements, ranging from lithium to sodium, are known as “highly active metals,” since they react with cold water to make hydroxide and hydrogen gas, among other things.

Active metals are defined as elements that react with very hot water or steam to create oxide and hydrogen gas. Elements ranging from magnesium to chromium are classified as active metals. Aluminum, for example, combines with steam to generate aluminum oxide and hydrogen gas, which are both toxic.

2Al(s) + 3H₂O (g)  → Al₂O₃ (s) +  3H₂(g)

Metals, ranging from iron to lead, may be used to substitute hydrogen in a variety of acids, including hydrochloric acid, dilute sulfuric acid, and nitric acid. When heated with hydrogen gas, carbon dioxide, or carbon monoxide, the oxidized forms of these metals undergo reduction. Metals may mix directly with oxygen until they reach copper, at which point they create a metal oxide. The elements present at the bottom, ranging from mercury to gold, are often found in their natural forms in nature, and their oxides are susceptible to thermal breakdown under moderate environmental circumstances.

Characteristics of Metals

As a result of the fast oxidation of metals at the extremities of their reactivity range, they are especially effective reducing agents, due to the high reactivity of the metals involved. All of these metals are susceptible to corrosion and oxidation.

1. The reduction capacity of the metals decreases as the metals below them in the chain continue to be reduced.
2. As the reactivity of a metal rises, the electropositive charge on the metal’s surface decreases as a result of this. Through interactions with metals in the activity series that are more active than hydrogen, it is feasible to create hydrogen gas from HCl or H₂SO₄ in a laboratory setting.
3. Metals that are towards the top of the reactivity spectrum may be used to dislodge metals from salty solutions.
4. To extract higher-ranking metals from ores and other compounds, more energy must be used than is now possible.
5. It can be observed in the graph above that as the activity sequence proceeds, the metals’ ability to donate electrons gets less and less effective.

Conclusion

We have learnt that a whole new material is produced in the course of a chemical reaction, and hence, a chemical change occurs in the course of one. In a chemical reaction, only atoms are rearranged. Reactants are chemicals that are a component of a chemical reaction. Products are the new compounds formed as a consequence of chemical reactions.