C Reaction with Mg Magnesium reacts very slowly with cold water but reacts rapidly with hot boiling water forming magnesium oxide and hydrogen. D Reaction with Zn and Al Metals like zinc and aluminum react only with steam to form their corresponding oxides and hydrogen.
E Reaction with Fe Iron metal does not react with water under ordinary conditions. The reactions occurs only when steam is passed over red hot iron and the products are iron II, III oxide and hydrogen.
F Reaction with other Metals Metals like copper, silver and gold do not react with water even under strong conditions. The order of reactivities of different metals with water is:. Reaction with dilute acids Many metals react with dilute acids and liberate hydrogen gas.
Only less reactive metals such as copper, silver, gold etc. The reactions of metals with dilute hydrochloric acid HC l and dilute sulphuric acid H 2 S O 4 are similar. With dil. HCl, they given metal chlorides and hydrogen whereas with dil. H 2 SO 4 , they give metal sulphates and hydrogen. Dilute nitric acid HNO 3 is an oxidising agent which oxidises metals, but does not produce hydrogen. The reactivity of different metals is different with the same acid.
Reaction with Fe Iron react slowly with dilute HC l or dil. H 2 S O 4 and therefore, it is less reactive than zinc and aluminum.
C Reaction with Cu Copper does not react with dil. HCl or dil. Reactivity with dil. Reactions of metals with salt solutions When a more reactive metal is placed in a salt solution of less reactive metal, then the more reactive metal displaces the less reactive metal from its salt solution.
For example, we will take a solution of copper sulphate blue coloured solution and put a strip of zinc metal in the solution. It is observed that the blue colour of copper sulphate fades gradually and copper metals are deposited on the zinc strip. However, if we take zinc sulphate solution and put a string of copper metal in this solution, no reaction occurs. This means that copper cannot displace zinc metal from its solution. Thus, we can conclude that zinc is more reactive than copper.
However, if we put gold or platinum strip in the copper sulphate solution, then copper is not displaced by gold or platinum. Thus, gold and platinum are less reactive than copper. Reactivity Series A Introduction We have learnt that some metals are chemically very reactive while others are less reactive or do not react at all.
On the basis of reactivity of different metals with oxygen, water acids as well as displacement reactions, the metals have been arranged in the decreasing order of their reactivities. The arrangement of metals in order of decreasing reactivities is called reactivity series or activity series of metals. The activity series of some common metals is given in Table. In this table, the most reactive metal is placed at the top whereas the least reactive metal is placed at the bottom. As we go down the series the chemical reactivity of metals decreases.
B Reasons for Different Reactivities In the activity series of metals, the basis of reactivity is the tendency of metals to lose electrons. If a metals can lose electrons easily to form positive ions, it will react readily with other substances.
Therefore, it will be a reactive metal. On the other hand, if a metal loses electrons less rapidly to form a positive ion, it will react slowly with the other substances.
Therefore, such a metal will be less reactive. For example, alkali metals such as sodium and potassium lose electrons very readily to from alkali metal ions, therefore, they are very reactive. C Displacement of Hydrogen from Acids by Metals All metals above hydrogen in the reactivity series i.
These metals have greater tendency to lose electrons than hydrogen. The metals which are below hydrogen in the reactivity series i. These metals have lesser tendency to lose electrons than hydrogen. D Reactivity Series and Displacement Reactions The reactivity series can also explain displacement reactions. In general, a more reactive metal placed higher in the activity series can displace the less reactive metal from its solution.
For example, zinc displaces copper from its solution. E Usefulness of Activity Series The activity series is very useful and it gives the following information: i The metal which is higher in the activity series is more reactive than the other.
Lithium is the most reactive and platinum is the least reactive. The metals at the bottom of the series are least reactive and, therefore, they normally occur free in nature. For example, gold, present in the reactivity series is found in Free State in nature. Reaction with oxygen All things that we see around are formed of one or more of the odd known elements.
From the time we wake up and till we go to sleep, we are dependent every second on one or the other compounds formed by the combination of these elements. There are more than trillions of compounds found over earth. Do you know the number of elements responsible for the formation of these many number of compounds?
You will be surprised to know that it is only 84 elements. Is it not astounding to know that atoms of these 84 elements form these trillions of compounds and help in human existence? What then is the chemical activity in which these atoms are involved to form huge number of compounds? What is the cause for this chemical activity? The following are the special features of noble gases: i They do not combine with themselves or their elements.
Thus, they are chemically inert. Owing to their inert nature, they are also called inert gases. Let us observe the number of electrons present in their outer shell.
Observation: Except helium, all other elements have 8 electrons in their outermost shell. Conclusion: The secret of inertness of inert gases is the stable duplet or octet configuration. Why do atoms combine? To answer this, let us first recall the reason for non-reactivity of noble gases. It is to be known that except the noble gases, all other elements have electrons in their outermost shell.
All the atoms except inert gases are unstable. Hence, the reason for the combination of atoms is to attain stability. It is the same reason, a reason for the cause of a chemical reaction also? Consider the reaction between sodium and chlorine. During this reaction, sodium loses one electron and chlorine gains one electron to form sodium chloride. They proposed a theory, based on electronic concept of atoms, known as electron theory of valency. The secret of stability of atoms Atoms with eight electrons in the outermost shell two in the case of Helium are chemically more stable.
Cause of chemical reaction The cause for chemical reaction is to attain stability. An atom achieves this by acquiring the octet configuration inert gas configuration in its outermost shell. Type of electrons The electrons present in the outermost shell of an atom are responsible for chemical reaction. The outermost shell is called valence shell and hence, the electrons present in it are called valence electrons.
The number of electrons taking part in a chemical reaction is called valency of that element. Attainment of Inert gas configuration The atoms of various elements achieve the nearest inert gas configuration, either by transfer losing or gaining or by sharing of electrons with another atom. This transfer or sharing of electrons results in the development of an attractive force between the atoms, which holds the atoms together by a bond.
The reason for not showing the inner shell electrons is that they are well-protected and do not involve in chemical reaction. Therefore, valence electrons are considered for the formation of the chemical bonds. Example: The electronic configuration of chlorine is 2, 8, 7. Thus, there are seven valence electrons.
The Lewis symbol of chlorine atom is. Ionic bond The chemical bond formed between two atoms by the transfer of one or more electrons from the valence shell of electropositive element metal to valence shell of electronegative element non-metal is called ionic bond. Oppositely charged ions attracted to each other and a bond between them is formed.
The bond existing between oppositely charged ions is called ionic bond or electrovalent bond. Sodium has one electron excess of octet and chlorine has one electron short of octet. To obtain stability, sodium should lose one electron and chlorine should gain one electron. When sodium combines with chlorine, sodium donates one electron to chlorine After transfer of electron, both form ions and attain stability.
Magnesium atom has two electrons excess of octet and each chlorine atom is one electron short of octet. When magnesium combines with two chlorine atoms, each chlorine atom accepts one electron from magnesium atom; one Mg atom can combine with 2 chlorine atoms. Properties of ionic compounds i Physical state Most of the Ionic compounds are hard crystalline, solids.
Reason: This is due to strong electrostatic force of attraction between cation and anions of ionic compounds Though ionic compounds are hard, they are brittle in nature. The behaviour of ionic compounds is much like glass, which breaks into many pieces on falling. Normally, the alignment is such that the oppositely charged ions are next to each other as shown: Owing to the impact on failing, the alignment is disturbed such that the ions with similar charge come next to each other. Since the charges repel each other, the crystal breaks along the line of force.
Reason: Melting and boiling of ionic compounds involve breaking of the lattice structure and setting the ions free. In a lattice, there are strong electrostatic forces between oppositely charged ions. Therefore, a considerable amount of energy is required to break these forces. Hence, the melting and boiling points of ionic compounds are high. Reason: Polar solvent like water overcome the forces of attraction between the ions in the crystal.
The resulting ions become mobile and disperse in all directions in polar solvent. Hence, conductivity is not possible. Ionic solutions are good conductors of electricity. The table below, explain reactions of metals with oxygen air , water, dilute acids, and other salts solutions, at various level of the reactivity series.
Reactivity of metals with oxygen, water, and acids. Nonmetal activity series is a list in which nonmetals are arranged in the decreasing order of their reactivity. Similar to metals, we can also arrange nonmetals in terms of their reactivity. During displacement reactions , a more active nonmetal displaces a less active nonmetal from a compound. The activity of a nonmetal depends upon its capability to gain electrons in the solution state to form positive ions.
The more readily nonmetal gains electrons, the more active it is, and higher up it is in reactivity series. Cesium and francium are the most reactive metals and are at the top of the reactivity series.
However, the quantity of francium produced until now is too little. Therefore, for all practical purposes, we consider cesium as the most reactive metal. Cesium reaction with water.
Video by Periodic Videos. Platinum is one of the least reactive metals and therefore lies at the bottom of the reactivity series. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal.
Due to its low reactivity, it found uses in the manufacture of laboratory equipment, electrodes, platinum resistance thermometers, dentistry equipment, and jewelry. Fluorine is the most active nonmetals and it displaces all other nonmetals in salt solutions. We determine the reactivity of metals, upon their capability to lose electrons in the solution state to form positive ions or cations. Therefore, the more readily metal loses its electrons, the more active it is, and higher up it is in reactivity series.
We determine the reactivity of nonmetals, upon their capability to gain electrons in the solution state to form negatively charged ions or anions. Therefore, nonmetals that gain electrons rapidly are more active than the others. The third class contains metals such as chromium, iron, tin, and lead, which react only with strong acids. It also contains even less active metals such as copper, which only dissolves when treated with acids that can oxidize the metal.
Metals in the fourth class are so unreactive they are essentially inert at room temperature. These metals are ideal for making jewelry or coins because they do not react with the vast majority of the substances with which they come into daily contact.
As a result, they are often called the "coinage metals. The product of many reactions between main group metals and other elements can be predicted from the electron configurations of the elements. Example: Consider the reaction between sodium and chlorine to form sodium chloride.
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