Category: Chemistry Notes PPT

Element 113

Nihonium is a recently discovered element which came into the existence in 2003. Today, 118 elements are known to us. 94 elements out of these are naturally occurring whereas elements from atomic number 95 to 118 are synthetic elements. Synthetic elements are those elements which are artificially made by researchers and scientists. Nihonium is also a synthetic element. This element is extremely radioactive and has a half-life of 10 sec. This means in 10 seconds it reduces to half of its quantity. It is placed in the p-block of the periodic table. Nihonium isotopes are quite unstable and only Nh-286 is found stable.

Nh Element

Symbol of Nihonium- Nh

The atomic number of nh-113

Atomic Mass of nh – 286

Group- 13

Period-7

Electronic configuration-[Rn]5f¹⁴6d¹⁰7s²7p¹

Discovery of the Element 113

Nihonium was first invented by Russian American collaboration JINR-JOINT INSTITUTE FOR NUCLEAR RESEARCH in Dubna, Russia in 2003 and then by RIKEN collaboration of Japan in 2004. In 2015, IUPAC-International Union of Pure and Applied Chemistry, recognized it as an element and gave rights for the discovery and naming to Riken. Thus Riken named element 113 as ‘Nihonium’ to honor Japan as ‘Nihon’ refers to Japan.

Experimentation

• Nihonium was synthesized by the bombardment of calcium ions on the element Americium with the atomic number 95 in the cyclotron. This lead to the formation of Moscovium which has an atomic number of 115.

• This element of moscovium undergoes an alpha decay process to form nihonium. 

• A very small amount of the element has been created till now.

Ununtrium

Nihonium is also known as the ununtrium. This name of Nihonium comes from the nomenclature rules proposed by IUPAC. 

According to these rules, elements that have an atomic number greater than 100 are named using certain codes decided by the IUPAC. By the systematic naming, those metals which are not discovered can also be named as the names are directly derived by the atomic number of the element itself.

Following is the Set of Codes for Numbers in Atomic Number-

 

Thus Following this Code Nihonium gets its Name as Ununtrium.

ATOMIC No. of Nh= 1     1      3

                                      ↓     ↓      ↓

                                   un   un     tri + um

                                        ↓

                                 ununtrium (Uut)

Properties of Element 113

Most of the properties of niobium are only predicted as it is short-lived. Some of the properties are as follows-

• Nihonium is found to be solid at temperature 20°C.

• The melting point, boiling point, and density of nihonium are unknown but they are predicted to be greater than its group members.

• Nh element belongs to the boron group(13 groups) of periodic table so its properties are assumed to resemble thallium.

• It is assumed to be denser than the thallium.

• Due to the spin-orbit splitting of 7p shell nihonium is chemically different from thallium and other elements of group 13.

• It is present in the 7th period of the periodic table.

• The crystal structure of Nihonium is assumed to be hexagonal close packing-hcp.

• Nihonium is not found naturally. It is considered to be entirely synthetic.

• Its oxidation states are assumed to be +1,-1 +3, and +5.

• Nihonium is assumed to have a size greater than thallium following the group trend. 

• It is considered to be a transactinide element.

Uses of Nihonium

It is used only for scientific research.No other use of Nihonium is known till now.

Effect on Health

As compared to the other elements in the periodic table, until now there is no considerable reason given for stating the harmful effects of Nihonium. It is because they are highly unstable and exhibit a short span of the half-life.

Isotopes of Nihonium

• Isotopes are those elements which are considered to have the same atomic number but different atomic mass.

• Nihonium also has 6 chemically synthesized isotopes from Nh²⁷⁸ to Nh²⁸⁶. Other than these two more isotopes are unconfirmed Nh²⁸⁷ and Nh²⁹⁰.

• Nh²⁸⁶ is the most stable as compared to others to all the other isotopes of Nihonium.

In the IUPAC system, the mono halogen-substituted alkanes are named haloalkanes. Their names are derived by prefixing the words fluoro, chloro, bromo or iodo (according to the halogen atom present) to the name of the longest straight chain present in the compound. In naming haloalkanes, the numbering of carbon atoms in the longest chain is done from the end from which the halogen atom is nearer. A suitable Arabic numeral indicates the halogen atom position. If side chains are present, their names are also mentioned in alphabetical orders, and suitable Arabic numerals also mention their positions. Bromoethane, chloroethane, 2 -bromobutane are some of the examples.

 

What Are Haloalkanes?

Hydrocarbons are regarded as the parent compounds of all other organic compounds. The replacement of hydrogen atoms in saturated aliphatic hydrocarbons by a halogen atom gives rise to haloalkanes. The halogen derivatives of alkanes are usually termed haloalkanes or alkyl halides. They are obtained by replacing a hydrogen atom present in an alkane with a halogen atom. Depending upon the number of hydrogen atoms replaced by halogen atoms, they are termed mono-, di-, tri-, tetra- or poly haloalkanes.

 

R-H  R-X

 

The general formula of haloalkanes is, where is a halogen atom. They can also be represented as an alkyl group. Some typical haloalkanes are, etc.

 

Process for the Nomenclature of Haloalkanes

The nomenclature of haloalkanes can be done in the following ways:

• The trivial or common system: In the trivial system, haloalkanes are termed as alkyl halides. The trivial name is obtained by adding the word halide to the name of the corresponding alkyl group. The derived name is always written as two separate individual words.

For example, methyl chloride is ethyl bromide.

In the trivial system, the prefixes n-, iso-, and neo- are generally used to describe different types of alkyl groups.

The prefix n- stands for normal. It is used to describe an alkyl group that contains straight chains of carbon atoms.

 

For example, is named as an n-propyl group.

The prefix iso is used to describe an alkyl group that contains a methyl branch at the end of the chain.

The prefix neo- is used to describe those alkyl groups which contain two methyl  branches at the same carbon atom at the end of the chain.

 

Classification of Haloalkanes

Depending upon the nature of the carbon atom to which the halogen atom is attached, the alkyl halides are further classified as follows:

• Primary alkyl halides: These are the haloalkanes in which the halogen atom is attached to a primary carbon. For instance, ethyl bromide.

• Secondary alkyl halides: These are the haloalkanes in which the halogen atom is attached to a secondary carbon. For instance, 2-bromopropane.

• Tertiary alkyl halides: These are the haloalkanes in which the halogen atom is attached to a tertiary carbon. For instance, tert. butyl chloride

()

Nomenclature of Haloarenes
The systematic names of halarenes or aryl halides are derived by adding prefixes fluoro, chloro, bromo, iodo (according to the halogen present ) before the name of the aromatic hydrocarbon. For instance, chlorobenzene, bromobenzene.

In the case of disubstituted or trisubstituted compounds, the relative positions of the substituent groups are indicated by the Arabic numerals. The numbering of the ring is done in such a way that the sequence gives the lowest sequence of numbers. In the case of disubstituted derivatives, the relative positions 1,  and 1,4 can also be indicated by prefixes ortho (o-), meta and para respectively.

 

Solved Examples

1. Write the IUPAC nomenclature and the structural formula of two such compounds containing five carbon atoms each in their molecule and which are optically active.
   Solution:
   The structural formula and the IUPAC names of such compounds are 2-chloropentane and 2-chloro-2-methylbutane, respectively.

2. Which one among the following pairs does have higher boiling points in these nomenclatures of haloalkanes?
   a. 1-bromopropane or 1-iodopropane
   b. 1-bromopropane or 1-bromobutane
   c. isobutyl bromide or t-butyl bromide

The Significance of Organic Compound Nomenclature

Organic chemistry covers the major portion of the syllabus in the chemistry of class 11 and 12 in CBSE. in the introduction chapters of chemistry in class 11 we get to know about different types of organic compounds or hydrocarbons which are formed by the combination of carbon ( C ), Oxygen (O)and hydrogen (H). The valency of a carbon atom is 4 which combines with 4 atoms of hydrogen to form the basic structure of methane (CH4) in organic chemistry. oxygen atoms with the valency of 2 often replace two hydrogen atoms to combine with the carbon atom. There are a vast number of compounds formed by the combinations of atoms of these 3 elements. And also the atoms of other elements like nitrogen (N), sulfur (S), and many more are also found in nature in a state combined with the hydrocarbons.

So it is essential for a definite structure of naming these compounds for easy recognition and remembering them. There was a time when any organic compounds found were given the local name for day-to-day use. Later it was found difficult to use different names in different places. With respect to general concern, it was decided to name all the compounds which would be acceptable all over the world. The body named as International Union of Pure and Applied Chemistry (IUPAC) was bestowed with the responsibility of identifying and naming all hydrocarbons available and developing a particular system of nomenclature for the naming of any hydrocarbons that would come up in the future. 

Haloalkanes are such a category of hydrocarbons named by IUPAC. Halogen atoms are the atoms of Fluorine, Chlorine, Bromine, Iodine. These halogen atoms are the deciding factor in the nomenclature of the compounds. The prefix used for the naming of the Organic compound is as follows: ‘floro’, ‘chloro’, ‘Bromo’, and ‘iodo’. The presence of such halogens imparts a certain aromatic nature to the substance. That is why such organic compounds are also known as aromatic hydrocarbons.

In both Chemistry and Physics, a nucleon can be either a proton or a neutron, Its role is considered as a component of an atomic nucleus. The number of nucleons in a nucleus describes the mass number of an isotope. 

 

They are also known to be composite particles that are made of three quarks bound together by a strong interaction. The strong interaction between two or more nucleons is called inter-nucleon interaction/nuclear force, which is also finally caused by the strong interaction. Also, before the discovery of quarks, the term “strong interaction” was referred to as just internucleon interactions.

What are Nucleons?

A nucleon is one of the subatomic particles of the nucleus of an atom. Each atomic nucleus can contain one or more Nucleons and these nucleons are surrounded by one or more electrons. 

 

Nucleons occupy a very small space within the nucleus. Each and every atom is made up of nucleons which are then divided into particles viz:  electrons, protons, and neutrons that orbit the nucleus. 

 

We can imagine an atom like a mini solar system with electrons orbiting a central star which is the atomic nucleus, made up of nucleons. We can see the image below:

 

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Nucleon Definition

Nucleon, is either of the subatomic particles, viz: the proton and the neutron, residing in the atomic nuclei. Protons are positively charged subatomic particles and neutrons are uncharged that behave identically under the influence of the short-range nuclear force, both in the way these subatomic particles are tightly bound in atomic nuclei and in the manner they are scattered by each other. 

 

This strong interaction between these particles is independent of electric charge. Unstable subatomic particles are heavier than nucleons that are hyperons and baryon resonances and they comprise a nucleon among their final decay products; the nucleon is, therefore, the baryon ground state. The antinucleons are of two types viz:  the antiproton and the antineutron.

Types of Nucleons

Primarily, there are two types of nucleons viz: protons and neutrons.  A proton carries a positive electric charge, and a neutron has a neutral electric charge, which means that it bears no electric charge on it. These two particles reside in the nucleus of the atom and generate a positive charge because the neutron has no charge at all.

 

We must note that protons and neutrons are the only best-known components of atomic nuclei so far.  These two particles can be found on their own not being part of the larger nucleus (residing inside it). 

Point to Remember

A particle viz: the proton is the nucleus of the hydrogen-1 atom on its own which is considered the most abundant isotope of hydrogen.

 

So, whatever particles that reside in the nucleus are nucleons; however, electrons revolve around the nucleus, so it is not considered nucleons. 

Binding Energy of a Nucleon

As we know, a nucleus consists of neutrons and protons; however,  the mass of the nucleus is less than the sum of individual masses of the proton and the neutron. The difference lies in the measurement of binding energy per nucleon that tightly holds nucleons. The binding energy can be determined by Einstein’s equation. The relationship is as follows:

 

Nuclear binding energy = ∆mc²

 

Here,

 

∆m = mass of a nucleon

 

c = speed of light, i.e., 3.8 x 10⁸ m/s

Since Δm for alpha particles is 0.0304 u (unit), this gives us the binding energy of a nucleon as 28.3 MeV.

What is a Nucleon?

So far we have been studying that a neutron is not a stable particle residing in an atom, but it can be used in nuclear reactions and scientific analysis. Protons and neutrons consist of three quarks. The proton has two up quarks, which is the lightest of all quarks and a  major constituent/portion of matter and a type of elementary/fundamental particle and one down quark, which is the second lightest quark, while a neutron is composed of one up quark and two down quarks.

 

These up and down quarks composed of protons and neutrons are an integral part of the atomic nucleus because they cannot persist as independent nucleons. The atomic nucleus holds the nucleons with a strong force of attraction. However, when the force is broken, a lot of power is generated and that power is termed nuclear energy which is similar to what we use in the production of nuclear bombs.

 

One must be very careful and understand that nucleons present in radioactive decay substances such as Uranium can be harmful since they can spread alpha radiation in a fraction of seconds. 

All about Nucleon: Attributes

• Composition of Nucleus: The nucleus is made up of protons and neutrons that are collectively called nucleons.

• Nuclear charge: The nucleus comprises protons and neutrons.

• Nuclear mass: We call the mass of the nucleus a nuclear mass. 

• Nuclear Size and shape: The nucleus is considered nearly spherical in shape.

The order of reaction of a chemical reaction refers to the relation between its rate and the concentration of the elements taking part in the chemical reaction. The reaction order is obtained by calculating the rate equation of the chemical reaction. From the rate equation, the entire composition of the mixture consisting of all the elements or species of the reaction can be known. In this article, definition of order of reaction, characteristics, determination and the different orders of reactions are discussed. Let’s first understand what is meant by the order of reaction.

What is the Order of Reaction?

The order of reaction is defined as the dependence of the concentration of all reactants in a chemical reaction on the rate law expression. For example, in a first order chemical reaction, the rate of reaction is entirely dependent on the concentration of one reactant in the reaction.

Order of a chemical reaction can be defined as the sum of power of concentration of reactants in the rate law expression is called the order of that chemical reaction. Reactions can be first order reaction, second order reaction, pseudo first order reaction etc. depending on the concentration of the reactants. Order of a reaction is an experimental value. It means it is an experimentally determined parameter. It can have fractional value as well.

Characteristics

There are some characteristics of order of reaction that are enumerated as follows:

• Order of reaction represents the number of reactant entities whose concentration affects the rate of reaction directly.

• The value of the order of reaction can be obtained by the summation of exponents of concentration terms in the expression of the rate of reaction.

• It does not depend on stoichiometric coefficients of the reactants in the balanced equation.

• Only the concentration of the reactants are considered and not that of the products formed in the chemical reaction.

• The value of reaction order can take an integer value or a fraction. It can even be zero.

If experimental rate law expression is given for a reaction, then we can deduce the order of that reaction as well. For example, consider a reaction – 

aA + bB [rightarrow] P

and rate law is given as – 

rate = k(Ax)(By)

order of reaction for the above reaction on the basis of given rate law can be written as follows – 

order of reaction = x + y

How to Find Order of Reaction?

Order of reaction is determined by experiment. Although if we know rate law expression determined experimentally then we can determine order of reaction using rate law. Order of reaction can be an integer or fractional value. Following orders of reactions are possible – 

• Order of reaction can be zero – In zero order reaction the concentration of reactant/s doesn’t affect the rate of a reaction. 

• Order of reaction can be negative integer – Negative integer value of order of reaction indicates that the concentration of the reactants inversely affects the rate of a reaction. 

• Order of reaction can be positive integer – Positive integer value of order of reaction indicates that the concentration of the reactants directly affects the rate of a reaction. 

• Order of reaction can be fractional value – Fractional value of order of reaction indicates a more intricate relationship between concentration of reactants and rate of reaction. Generally, complex reactions possess fractional values of order of reaction.

Following Methods Can be Used For Determination of Order of Reaction –

• Differential Method – It is also called the initial rates method. In this method concentration of one reactant varies while others are kept in constant concentration and initial rate of reaction is determined. Suppose if three reactants A, B and C are taking part in the reaction then in this method we keep varying concentration of one reactant (for example reactant A) while concentration of other reactants such B and C constant. 

• Graphical Method – This method is used when only one reactant takes part in the reaction. In this method if we draw a graph between logA (where A is concentration of reactant) and t (time) and it’s a straight line then reaction follows a first order.  In the same way if we draw a graph between 1/A and t and get a straight line then reaction follows second order. While if we draw a graph between 1/A² and t and get a straight line then the reaction is a third order reaction. 

• Integral Method – In this method concentrations of the reactants are compared with the integral form of the rate law. It is used for verification of initial rate methods.

Difference Between Molecularity and Order of Reaction 

Molecularity and order of reaction both give information about the chemical reaction but are very different from each other as one tells about the number of molecules taking part in reaction while another one tells about the relationship between rate of reaction and concentration of reactants. For your better understanding we are providing you here pointwise difference between molecularity and order of reaction- 

Zero Order Reaction 

In these reactions the rate of reaction doesn’t depend upon the concentration of reactants. It means change in concentration of reactants doesn’t affect the rate of reaction. 

Example –

[ 2NH_{3}(g) overset{text{Fe or W as catalyst }} rightarrow N_{2}(g) + 3H_{2}(g) ]

First Order Reaction 

In these reactions the rate of reaction depends on the concentration of one reactant only. There can be many reactants in the reaction but concentration of only one reactant will affect the rate of reaction. Concentration of other reactants will have no effect on order of reaction. 

Example – [ N_{2}O_{5} rightarrow N_{2}O_{3} + O_{2} ]

Rate = k[N2O5]

Second Order Reaction 

In these reactions the rate of reaction depends on the concentration of two different reactants or square of concentration of one reactant. 

Example – [ 2NO_{2} rightarrow 2NO + O_{2} ]

Rate = k[NO2]2

[ CH_{3}COOC_{2}H_{5} + OH^{-}] [rightarrow] [CH_{3}COO^{-} + C_{2}H_{5}OH ]

Rate = k[CH3COOC2H5] [OH–]

Pseudo First Order Reaction 

Those reactions which are not of 1st order but approximated or appear to be of 1st order due to higher concentration of the reactant/s than other reactants are known as pseudo first order reactions. 

Example – Hydration of alkyl halide

 

[ CH_{3}I + H_{2}O ] [rightarrow] [CH_{3}OH + H^{+}+ I^{-} ]

Rate of reaction = k [CH3I] [ H2O]

As methyl iodide is also used in aqueous solution form so the concentration of water is far higher than methyl iodide. 

[CH3I] <<< [ H2O]

So, concentration of water doesn’t change much and can be approximated as no change or constant. 

Now we can write – Rate of reaction = k’ [CH3I]

Where k’ = k [H2O]

Thus, the reaction appears to be first order, but it is actually of second order that’s why it is known as pseudo first order reaction.

The chemical process of oxidation-reduction, better known as redox reaction is a common phenomenon around the world. It is also an essential contributor to the metabolic process, whereby nutrient oxidation leads to energy release and enables life forms to thrive. Exposure of various elements, as well as compounds, causes combustion and release of water, carbon dioxide, and energy. Thus, to gain a better understanding of reactions like redox and combustion, one must be aware of oxidation state or OS, a chemical characteristic exhibited by various elements.

 

The term redox is created by combining two words RED for reduction and OX from oxidation. Where two major processes of reduction and oxidation took place simultaneously and satisfy the molecular requirement of each other.

 

The displacement reactions are classic examples of redox reactions where one species is oxidized and loses electrons while the other is being reduced by gaining that same electron.

What does Oxidation State Mean?

The oxidation number or the oxidation state is theoretically a charge of an atom if all of its bonds to several different atoms were fully ionic. They define the level of oxidation of an atom in a chemical compound.

On the conceptual level, the oxidation state can be either represented by using integrals like positive, negative, or zero.

 

In other words, OS refers to a specific number assigned to elements in different chemical combinations. These numbers are a representation of electron quantity lost or gained by an element’s atom to result in a chemical bond with another element. Also interchangeably used with oxidation number, it is used for the determination of changes that are taking place in a redox reaction. It has a similar numerical representation as valence electrons but is typically differentiated from formal charge. To better understand the oxidation state definition, you must also know that elements must act as a reducing agent on oxidation, resulting in the release of electrons.

Origin and Discovery of Oxidation State

The popular French chemist, Antoine Lavoisier first used oxidation as a means to describe the reaction of oxygen with any substance. Later experiments remarkably identified oxidation to result in electron loss. The use of the term oxidation was thus expanded to other reactions that identified electron loss, whether or not it involved oxygen, et. Thus, it increased its scope of usage. Such electron losses were thus identified with values known as oxidation state. One could thus define oxidation number or state by putting a value to such electron losses during a reaction, which usually stood as integers. At times, the OS can also be represented as a fraction. For instance, the OS of iron in [Fe_{3}O_{4}] is valued at 8/3. Before moving on to more about oxidation number or state, take a brief look at the process of oxidation.

In simple words, Lavoisier uses the term oxidation for the first time in history. It represents the reaction of a substance with oxygen.

After a long period of time, it was discovered that the substance, upon being oxidized, loses its electrons. It further extends to include other reactions where electrons are lost. Except for the fact whether oxygen was involved or not.

What does Oxidation Entail?

The contact between the oxygen molecules and substances causes an Oxidation reaction. It can be simply described as an atom’s enhanced oxidation state through a chemical reaction. It’s the exact contrary part of the reduction reaction. In both reactions, the transfer of electrons is required.

Oxidation refers to a chemical reaction that involves electron movement between the elements of any compound. The process’s character is exhibited when an element donates electrons. It is also denoted by an increased oxidation state. A common example of oxidation is the reaction of iron (Fe) with oxygen ([O_{2}]). The reaction of these two elements results in the formation of rust, whereby the electrons lost by iron are gained by oxygen.

Oxidation States – The Highest and the Lowest

While oxidation involves the increase in oxidation state, its decrease is denoted by reduction. However, there have been quantity limits identified for the state, whereby the highest OS has been marked at +9 for tetrox iridium and the lowest in the case of carbon in methane or [CH_{4}] at -4.

Identifying oxidation states in elements or compounds is based on the following few rules one must take care of. You must also follow these rules in the right order and consider the one appearing first in order in the case of conflict.

Rules to identify and assign Oxidation States

Some other examples that satisfy the OS rules are mentioned below.

1. In [NH{_{4}}^{+}], the oxidation state of nitrogen is -3 and that of hydrogen is -1.

2. In [SO{_{4}}^{2-}], oxygen’s OS is -2 and sulphur, +6.

3. For [OH^{-}], OS for oxygen stands at -2 and that for hydrogen at -1.

Also, while the oxidation states are mostly represented by integers, some can also have fractional values. Nevertheless, the rules still apply when assigning the OS to elements in a given compound. If the ions of an element in a given compound can be separated, the OS is determined by the process of fragmenting, which can result in fractional values for the element.

Quick Question 1: Does oxidation always involve oxygen?

Ans: Oxidation happens when an ion atom loses electrons (one or more) in the chemical reaction. During the oxidation process, the oxidation state of the chemical species increases. This reaction doesn’t require oxygen necessarily.

 

Basically, the term is used when oxygen happens to lose an electron during the reaction.

Oxidation Number Calculation

You can calculate an atom’s oxidation number in a given compound by taking care of the following few computation rules.

1. Remember rule 1 suggests every atom that is free or non-combined carry an OS of ‘0’. As per rule 2, ions with only one atom carry a charge that equals the ion’s OS.

• While the OS in the case of oxygen stands at -2, some exceptions to this rule include – 

• Each oxygen atom carries an OS of -1 in the case of peroxides.

2. Oxygen atoms carry an OS of –(1/2) in the case of superoxides.

3. When forming a bond with fluorine, the OS of oxygen can vary.

4. For hydrogen bonding with metals carrying two elements, OS is -1.

5. OS is positive for halogens like chlorine, iodine, and bromine when combined with oxygen.

6. The sum of oxidation numbers added for different atoms in a compound should equal zero.

7. The OS of an ionic compound equals the ion’s charge when calculating it for polyatomic ions.

Quick Practice Questions

Assign oxidation numbers to the elements of the following compounds using the rules and the calculation method given above.

• [H_{2}SO_{4}]

• [CuSO_{4}]

• [FeCl_{3}]

• [S_{2}O{_{3}}^{2-}]

• NaH

• The difference between the oxidation number and oxidation state are terms with interchangeable use, they are not exactly the same. The following points state the difference between oxidation state and oxidation number.

• Although oxidation number and oxidation state are terms with interchangeable use, they are not exactly the same. The following points state the difference between oxidation state and oxidation number.

Oxidation States and Numbers:

Now, take a look at some other essential details on oxidation state and numbers that can help in the calculation.

When expressed in terms of the periodic table, the oxidation numbers of various elements can be identified based on the following properties.

• Alkali metals of Group 1A carry an OS of -1.

• Alkali earth metals of Group 2A carry an OS of -2.

• Elements in Group 3A often exhibit an OS of +3. They can also have an OS of +2 or +1.

• OS for elements in Group 3A remains in the range of -4 and +4. (Image to be added soon)

• In the case of non-metals, the OS can vary on a wide range. However, when calculated, subtracting the minimum OS from the maximum results in +8.

• The maximum OS of an element can go up to 7 subtracted by its group number.

• Elements of Group 1 have an OS of +1.

• For Group 2, it is +2 and for Group 3, +3.

• Group 4 elements range between -4 and +4 while Group 5 elements are between -3 and +5. Group 6 and 7 elements range from -2 to +6 and -1 to +7
  .

• For inert gases, the OS is always zero.

While this was all about oxidation state, its exhibition, and properties for different elements, you can carry on with your exam preparation by referring to chemistry solutions as well. hosts a range of study material online to assist students with thorough preparation. 

Download our app today for a streamlined approach to exam preparation.

Quick Question 2: Does oxidation produce heat?

Ans: The Oxidation reaction is a reaction where there is a loss of electrons, generally through the addition of oxygen or reduction of hydrogen. The oxidation of glucose to pyruvate emits energy, which would be listed as heat, but there is no solid proof for this. 

Types of Redox Reactions

There are five main types of redox reactions mentioned as follows:

A combination reaction involves the combination of two different compounds. By this combination, a singular compound is formed. 

[ X + Y rightarrow  XY]

Here are some of the common examples of combination reactions.

[4Fe + 3O_{2} rightarrow  2Fe_{2}O_{3}]

[2Ca + O_{2} rightarrow  2CaO]

In this type of redox reaction, the breakdown of the compound happens into various compounds. The decomposition reactions are the contrary of combination reactions.

Here are some basic examples of these types of reactions:

[2H_{2}O rightarrow  2H_{2} + O_{2}]

[H_{2}CO_{3} rightarrow  H_{2}O + CO_{2}]

In the above reaction, the total compound is broken down into the small chemical compound in the form of XY → X + Y

In some specific cases, it’s deduced that the decomposition reactions do not fulfill the criteria of redox reactions.

One such example is as follows:

[CaCO_{3} rightarrow  CaO + CO_{2}]

In this type of reaction, an ion, atom, or molecule in a compound is interchanged by an ion atom or molecule in another compound. Simply, it is an exchange deal between compounds. 

For example [A + BC rightarrow  AC + B]

It can also be categorized into the following sub-category. 

1. Metal displacement Reaction

2. Non-metal displacement Reaction

1. Metal Displacement

In this kind of displacement reaction, one metal present in a compound is displaced by the metal present in another metal. These kinds of reactions are basically used in the metallurgical processes where pure metals are extracted from their ores.

Here’s a common example of a metal displacement reaction

[CuSO_{4} + Zn rightarrow  Cu + ZnSO_{4}]

2. Non-Metal Displacement

Non-Metal Displacement reactions involved hydrogen displacement. There are rare cases where oxygen displacement happens in these types of reactions. 

This type of redox reaction happens between an oxidant and a fuel. By using atmospheric oxygen. This produces a gaseous substance called smoke.

Here is an example of a reaction.

[CH_{4}(g) + 2O_{2}(g) rightarrow  CO_{2}(g) + 2 H_{2}O(g)]

In the disproportionation reactions, a single reactant is oxidized and reduced. It’s also called a Dismutation reaction. 

Here’s a convenient example:

[Mn_{2}O_{3} rightarrow  Mn_{2} + MnO_{2}.]

In this reaction, one compound of intermediate oxidation state breaks into two compounds, where there is a difference between oxidation states i.e. one compound is of higher oxidation states while the other is lower oxidation states.

Before going into the details of P- block elements, it is essential that one must have good knowledge about the modern periodic table in general. It is a display of all the known chemical elements in tabular form. The periodic table serves a useful purpose in going through all the chemical elements. It is used extensively in Chemistry and even Physics. Dmitri Mendeleev was the first person to propose a periodic table that was largely accepted. This was done in 1869.

The periodic table is divided into large areas or rough columns which are called blocks the block is categorized based on the atomic orbitals of the elements that their valence electrons or vacancies lie in. These are as follows:

• s-block

• p-block

• d-block

• f-block

• g-block

The rows of the table are referred to as “Periods.” Each column on the other hand is referred to as a group.

In this article, we will focus mainly on p- block element and its properties. p block is a significant block consisting of many important elements. These can be located on the right side of the periodic table. 

The elements of the group 13 – 18 come under the p – block elements. In these elements the last electron enters in the outermost p – orbital. They have ns2np1-6 electronic configuration in valence shell, helium being an exception. These elements show the maximum oxidation state equal to the sum of electrons in the outermost shell or valence shell. Most of the elements of the p – block form covalent compounds although some elements form ionic compounds (such as halogens) and coordination compounds as well. p-block contains elements which are either metals, non – metals or metalloids. p-block elements include the group of halogens and inert gases. First member of each family of the p-block elements is given below in the table with their general electronic configuration and oxidation states. p-block has the most electronegative element which is fluorine. Elements of p-block generally form acidic oxides. Many elements such as C, Si, Ge, O, N etc. also show phenomena of allotropy. Property of catenation is also shown by many elements.  

 

 

Group 13 Elements: The Boron Family 

Group 13 is the first group of p-block elements. First element of this group is Boron which is the only metalloid of this group. This is the reason that group 13 is also known as the boron family.  

 

 

 

 

 

Important Trends and Anomalous properties of Boron 

Important trends of group 13 elements are listed below –

• Trichloride, Tribromides and Triiodides of group 13 elements are covalent in nature and can be hydrolyzed in water. 

• Monomeric trihalides of these elements are strong Lewis acids. 

BF3 + :NH3 🡪 NH3-BF3

Anomalous properties of Boron are listed below –

• Boron shows quite higher melting and boiling points than other elements of group 13. 

• Boron forms only covalent compounds while other elements of the group 13 form both ionic and covalent compounds. 

• Boron is a metalloid while other elements of the group 13 are metals. 

• Oxides and hydroxides of boron are acidic in nature while oxides and hydroxides of other elements of the group are amphoteric and basic in nature. 

 

Some Important Compounds of Boron

 

Uses of Boron and Aluminium and their Compounds

Boron, aluminium and their compounds are of great importance biologically and environmentally. Few of their applications are listed below –

• Boron fibers are used in the bullet proof jackets. 

• Boron is used in light composite material for aircrafts. 

• Boron compounds are used in glass making, borax beads test, jewelry industry, antiseptic. 

• Various boron compounds are used as rubber vulcanizer, rocket propellant, flame speed accelerator etc. 

• Aluminium is used in wires as it’s a good conductor of electricity. 

• Al is used in various utensils as well as it’s a good conductor of heat. 

• It is used in pipes, rods, tubes etc. 

• Al is used in many alloys of Zn, Mg, Cu, Mn etc. 

• Compounds of aluminium are used in manufacturing of rubber, pharmaceuticals, textiles and as pesticides, lubricants and wood preservatives. 

• Al compounds are used in preparation of many compounds. 

• Aluminium chloride is used as a catalyst in Friedel – Craft acylation reaction.

 

Group 14 Elements: The Carbon Family 

Group 14 is the second group of p-block elements. First element of this group is carbon which is found in large quantities in nature and the 7th most abundant element in the earth’s crust. This is the reason that group 14 is also known as the carbon family. Apart from this carbon also shows various unique properties as well such as catenation etc. The branch of chemistry – Organic Chemistry is based on carbon and its compounds. 

 

 

 

 

Important Trends and Anomalous Behavior of Carbon 

Carbon differs from other members of the group 14. This is because of small size of carbon atom, higher electronegativity, higher ionization enthalpy, unavailability of the d-orbital and catenation property of carbon. 

 

In carbon d – orbital is not available for bonding, only s and p orbitals are available for bonding. This is the reason it can accommodate only 4 pairs of electrons in bonding. 

Carbon can form multiple bonds with another carbon atom and other atoms of other elements which possess high electronegativity and small size. For example, C=C, C=O, C=N etc. Carbon can form chain and ring compounds. It shows the property of catenation. 

 

Many allotropes of carbon are found in nature due to its catenation property.

 

Allotropes of Carbon 

Many crystalline and amorphous allotropic forms of carbon are found in nature. The property of elements to exist in two or more different forms is called allotropy and the different forms are called allotropes of that element. Here, we are discussing three main allotropes of carbon in the table given below –

 

 

Uses of Carbon 

Carbon is a very useful element. Organic chemistry is based on carbon and its compounds. Few of its uses are listed below – 

• Graphite is used in batteries and filaments due to its electricity conducting property. 

• Diamond is used in glass cutting. 

• Graphite is used in the pencils. 

• Graphite is used to make crucibles which are inert to acids and alkalies. 

• Graphite is used in tennis rackets, fishing rods, aircrafts etc. 

• Diamond is used in ornaments, polishing, lapping etc. 

 

Oxides of carbon are of great importance and are found in nature. Here we are discussing two main oxides of carbon in the table below –

 

Some Important Compounds of Carbon and Silicon

 

95% of the earth’s crust is composed of silica and silicates. Being a metalloid, it possesses some characteristics of metals and some of non – metals. That’s why it becomes of more use. Silicon forms many compounds which are of great use commercially. Here we are discussing three main compounds of silicon in the table below –

 

 

This ends our coverage on the summary of the unit “The p-block elements”. We hope you enjoyed learning and were able to grasp the concepts. You can get separate articles as well on various subtopics of this unit such as carbon family, elements of group 14, etc. on the website. We hope after reading this article you will be able to solve problems based on the topic. We have already provided detailed study notes or revision notes for this unit, which you can easily download by registering yourself on the website. Here in this article, we have discussed the unit in a summarized way with the emphasis on important topics of the unit.  If you are looking for solutions of NCERT Textbook problems based on this topic, then log on to the website
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