MPTET Varg 1 Chemistry Mock Test - 2 - MPTET MCQ

सही उत्तर है - ‘निर्मम’।

• ‘जो ममत्व से रहित हो’ उपयुक्त वाक्यांश के अर्थ को व्यक्त करने वाला सही शब्द ‘निर्मम’ होगा।

स्पष्टीकरण
अन्य विकल्प :

• जिसे कोई रोग न हो : निरामय।
• अनुराग न रखनेवाला : निर्मोही।
• जिसमें दया न हो : निष्ठुर।

महत्वपूर्णबिंदु
अन्य महत्वपूर्ण वाक्यांश के लिए एक शब्द :-

• जो किसी भी गुट में नहीं हो – तटस्थ।
• ईश्वर में आस्था रखने वाला – आस्तिक।
• ऊपर कहा हुआ – उपर्युक्त।
• जो परीक्षा में पास न हो – अनुत्तीर्ण।

अन्यसंबंधित बिंदु

• किसी वाक्य में प्रयुक्त या स्वतन्त्र, किसी वाक्यांश के लिए किसी एक शब्द का प्रयोग किया जाता है,
  जो उस वाक्यांश के अर्थ को पूरी तरह सिद्ध करता हो तो उसे वाक्यांश के लिए एक शब्द कहते हैं, अर्थात
  अनेक शब्दों के लिए एक शब्द को प्रयुक्त करना ही वाक्यांश के लिए एक शब्द कहलाता है।

The correct answer is 'woe'.

Explanation

• Jubilation: A feeling of great happiness, especially because of a success
  • ​E.g.- The news was greeted with jubilation.
• Woe: A strong feeling of sadness
  • ​​E.g.- The city's traffic woes are well-known.

Hence, the correct answer is 'woe'.

Other Related Points

• Happiness: The feeling of being happy
  • ​​E.g.- It was only later in life that she found happiness and peace of mind.
• Festivity: The parties, meals, and other social activities with which people celebrate a special occasion
  • ​​E.g.- Come in and join the festivities!​
• ​Triumph: A great success or victory; the feeling of happiness that you have because of this
  • ​​​E.g.- The team returned home in triumph.

The correct answer is Karnataka.

Explanation

• In the BCCI Under-19 women's cricket tournament played in Ahmedabad, Madhya Pradesh won the championship by defeating Karnataka.
  • Madhya Pradesh defeated Karnataka by 26 runs in the final played in Ahmedabad.

Other Related Points

• Earlier, Madhya Pradesh had made it to the final by defeating Delhi in the semi-finals.
• For Madhya Pradesh, opener Kanishk Thakur scored 52 runs in 60 balls with the help of four fours.
• The Directorate of Sports and Youth Welfare is a department of the state government of Madhya Pradesh is responsible for development in the field of sports and youth welfare.
• Madhya Pradesh Cricket Association (MPCA) is one of the major cricket governing provincial units affiliated to the Board of Control for Cricket in India (BCCI). MPCA is a regular participant in all domestic tournaments organized by BCCI.

Piaget and Vygotsky proposed theory regarding the role of language for development and the relationship between language and thought.

• According to Piaget, thought comes before language, which is only one of its forms of expression. The formation of thought basically depends on the coordination of sensory-motor schemes and not of language. This can occur only after the child has reached a certain level of mental abilities, subordinating herself, to the thought processes. The language allows the child to evoke an object or event absent at the communication of concepts.
• Piaget insists that the language and thought of the child are aspects of cognitive processes. The intellectual development of the child can be understood through his/her language and thought processes.
• Piaget primarily concentrated on the cognitive aspect, another dimension was added by Vygotsky
• According to Vygotsky, thought and language is interdependent processes, from the beginning of life. The acquisition of language by the child modifies its higher mental functions: it gives a definite shape to thought, enables the emergence of imagination, memory usage, and action planning.
• All fundamental cognitive activities including language take place in a matrix of social history. He believed that cognitive skills and patterns of thinking are not determined by innate factors but are the product of the interaction between the individual and the socio-cultural institution where the individual grows up.

Hence, from the above point it is clear that according to Piaget, a thought emerges first and according to Vygotsky, language has a profound effect on thought.

"Persons with disabilities" include those who have long-term physical, mental, intellectual, or sensory impairments which in interaction with various barriers may hinder their full and active participation in society on an equal basis with others.

Key Points -

The latest legislation passed by the Indian Parliament for people with disability is the Rights of Persons with Disabilities Act.

• The Rights of Persons with Disabilities (RPWD) Act, 2016 was enacted on 28.12.2016 and came into force on 19.04.2017.
• 'The RPWD Act 2016' has replaced 'The Person with Disabilities Act, 1995' which was enacted 21 years back.

Important Points

• It is an act that ensures equal opportunities for the people who suffer from 40% of disabilities.
• It covers 21 disabilities and enhances the reservation quota (3% to 4%) in government jobs for disabled persons.
• It focuses on making all public buildings disabled-friendly by providing ramps, slopes, auditory signals, etc.

Thus, it is concluded that the Rights of Persons with Disabilities Act is the latest legislation passed by the Indian Parliament for people with disability.

Hint

• National Education Policy: The Union Cabinet has approved the new National Education Policy 2020 intending to introduce several changes in the Indian education system from the school to the college level. Its aims at making “India a global knowledge superpower”. The two earlier education policies were brought in 1968 and 1986.
• The person with Disabilities (Equal Opportunities, Protection of Rights and Full Participation) Act: This act come into enforcement on February 7, 1996. This law is an important landmark and is a significant step in the direction to ensure equal opportunities for people with disabilities and their full participation in nation-building.
• Right to Education Act: The Right to Education Act 2009, also known as the RTE Act 2009, was enacted by the Parliament of India on 4 August 2009. It describes modalities of the importance of free and compulsory education for children aged between 6-14 years in India under Article 21 (A) of the Constitution of India.

The correct answer is option 1 i.e.: A-IV, B - I, C - III, D - II
Solution:
(a) Parts per million (ppm): When a solute is present in trace quantities, it is convenient to express the concentration in ppm.

• PPM = mass of solute × 10⁶ / mass of solution.
• Since we are multiplying the mass of solute by 10⁶ it makes the solution more dilute.

(b) Molarity (M): Molarity of a solution is the number of moles of the solute per liter of solution (or a number of millimoles per mL. of solution)

• Molarity = no. of moles of solute in gram/volume of solution in L
• Hence unit becomes mol L^-1.

(c) Molality (m): It is the number of moles of gram molecules of the solute per 1000 g of the solvent.

• Molality = no. of moles of solute in gram/mass of solvent in kg.
• Molality (m) does not depend on temperature since it involves the measurement of the weight of liquids.

(d) Mole fraction (X): Mole fraction may be defined as the ratio of the number of moles of one component to the number of moles of all the components (solvent & solute) present in the solution.

• Mole fraction = Amount of constituent in moles/total amount of all constituent in a mixture in moles
• Thereby it is a unitless quantity.

Concept:

Alcohol:

10 alcohol

• A primary(1⁰) alcohol is alcohol in which the hydroxyl group is bonded to one alkyl group.
• For example, R-OH

20 alcohol

• A Secondary (2⁰) alcohol is alcohol in which the hydroxyl group is bonded to two(same or different) alkyl groups.
• For example, R-CH(OH)-R

30 alcohol

• A tertiary (3⁰) alcohol is alcohol in which the hydroxyl group is bonded to three(same or different) alkyl groups.
• For example, R-C(R)(OH)-R

Explanation:

Oxidation method:

• Primary alcohol on oxidation gets converted to carboxylic acid.
  • For example, R-CH₂OH ----- ^H+/KMnO₄-----> RCOOH
• Secondary alcohol on oxidation gets converted to ketones.
  • For example, R₁-CH(OH)-R₂------^H+/KMnO₄------>R₁
• Tertiary alcohol on oxidation has no effect.
  • For example, R-C(R)(OH)-R-------^H+/KMnO₄-------> No effect

Lucas Test:

• A chemical test in which Lucas reagent that is Con. HCl and anhydrous ZnCl₂ are used.
• Primary alcohol does not give white precipitate at room temperature.
• Secondary alcohol gives white precipitate after five to ten minutes.

Tertiary alcohol gives white precipitate immediately.

Victor Mayer method:

In this test, alcohols are treated with HI, AgNO_3, and HNO₂ successively and then the solution is made alkaline.

1. Primary alcohol gives blood red color.
2. Secondary alcohol gives blue color.
3. Tertiary alcohol remains colorless.

The oxidation method, Lucas test, and Victor Mayer method are the three different methods to distinguish between primary, secondary, and tertiary alcohol.

Hence All of these are correct.

Gatterman - Koch reaction-

• Gattermann Koch Reaction Mechanism begins with the formation of the reactive species with the help of the acid.
• The overall aim of the reaction is to attach a formyl group (-CHO group) to an aromatic system.
• An example of the Gattermann – Koch reaction is given below.
  
• The Gattermann – Koch reaction is not applicable to phenol and phenol ether substrates.
• If zinc chloride is used as a catalyst in the Gattermann – Koch reaction, traces of copper(I) chloride are often necessary since it acts as a co-catalyst.

Important Points
Etard reaction-

Concept:

• Sigma bond is formed by end-to-end overlapping of the orbitals. Whereas, pi-bond is formed by lateral or side-by-side overlapping of p-orbital.

Explanation:

• Each double bond have one pi bond and one sigma bond. Triple bond will have two pi bonds and one sigma bond.
• In the structure given above have C-H, C-C and C = C bonds. Each of this have one sigma bond.
• Only C = C have one pi bond along with sigma bond.
• In the diagram given below, red numbers indicate the pi bonds and black numbers indicate the sigma bonds.

Conclusion:

• Therefore, in the structure given above have 5 π bonds and 19 σ bonds.

Other Related Points

• Given structure is of Naphthalene, which is an aromatic compound. π bonds are not localized at a specific bond, and there is complete conjugation.
  
• Dotted circle in structure (II) shows that π electrons are distributed over all the 10 carbon atoms.
• Therefore, there is no complete double bond or complete single bond.

CONCEPT:

When walking on the road there is friction (one type of resistance) between the road and the foot. It means friction between two layers. Such friction is also observed in a flow of liquid. The fraction between layers of the liquid during liquid flow, this fraction is defined as ‘Viscosity’ in the case of fluid.

• Viscosity:

• Viscosity is defined as the force of attraction between two layers of liquid moving past one another with different velocities.
• Consider a liquid flowing through a narrow tube. Imagine the liquid to be made up of a large number of thin cylindrical layers.
• The layers which are in contact with the walls of the tube are almost stationary. As we move from the walls of the tube toward the center of the tube, the velocity of cylindrical layers increases. It is maximum at the center.
• The force of attraction between two cylindrical layers when each having area A sq. cm separated by a distance X cm and having a velocity difference of cm/s is given by

=

=

EXPLANATION:

• Viscosity coefficient of viscosity:​

​

if, x= 1cm

A= 1 sq.cm

v =1 cm/s then η= f

When the force of attraction required to maintain a velocity difference of 1 cm/s between two parallel layers, 1 cm apart and each having are 1sq.cm., is called co-efficient of viscosity.

Unit of η:

f = force of attraction, newton

x = meter

A= meter²

meter second^-1

η = newton × meter× meter^-2× meter × second

= newton × second × meter^-2

CONCLUSION: Therefore, the SI unit of viscosity coefficient (η) is Nsm–2

Concept:

• The oxidation state of an uncombined element is zero.
• The sum of the oxidation states of all the atoms or ions in a neutral compound is zero.
• The sum of the oxidation states of all the atoms in an ion is equal to the charge on the ion.
• The more electronegative element in a substance is given a negative oxidation state. The less electronegative one is given a positive oxidation state.

Explanation:
First of all, we will calculate the oxidation number of all the given compounds.

Let the oxidation number of Cr be x.
x + 2*(−2) = −1
x − 4 = −1
x = +3
Thus, the oxidation number of Cr is +3

Let the oxidation number of Cl be x.
x + 3*(−2) = −1
x − 6 = −1
x = +5
Thus, the oxidation number of Cl is +5.

Let the oxidation number of Cr be x
x + 4 × (−2) = −2
x − 8 = −2
x = +6
Thus, the oxidation number of Cr is +6.

Let the oxidation number of Mn be x
x + 4 × (−2) = −1
x − 8 = −1
x = +7
Thus, the oxidation number of Mn is +7
Conclusion:
Thus, the correct increasing order oxidation number of the central atom is

• If the value of ΔG value is negative then the reaction is spontaneous.
• If the value of ΔG is positive then the reaction is non-spontaneous.

The relation is given by:
→ ΔG = ΔH – T ΔS.

• It is given that ΔH = 35.5 KJ / mol = 35500 J/ mol, ΔS = 83.6 JK^-1 mol^-1
• To be spontaneous, ΔG < 0
• Or, ΔH – TΔS < 0
• Or, ΔH < TΔS
• Or, TΔS > ΔH
• Or, T x 83.6 > 35500
• Or, T > 424.64 K
• So temperature should be greater than 424.64 K i.e. about 425 K.
• So, the correct answer is option 3.

The correct answer is Antacid.

• Milk of magnesia is Magnesium hydroxide.
• Formula-: Mg (OH)2.

Explanation

• As an antacid, magnesium hydroxide works by simple neutralization, where the hydroxide ions from the Mg (OH)₂ combine with acidic H⁺ ions produced in the form of hydrochloric acid by parietal cells in the stomach to produce water.
• In Stomach:

  • HCl + H2O à H₃O⁺ + Cl-

    Mg (OH)₂ (s) + 2 H₃O⁺ (aq) = 4 H₂O (l) + Mg²⁺ (aq).

• It thus neutralizes the acid produced in the stomach and works as an Antacid.

• The acidity of aromatic compounds is determined by their ability to donate hydrogen ions in solution.
• The greater the ease of donation or liberation of the hydrogen ions, the stronger is the acid.
• The acidic proton of an aromatic compound is generally attached to an electronegative atom and the strength of the acidity is greatly influenced by the substituents or groups attached to the ring and their position.

• The stability of the conjugate base - if the negative charge is resonance stabilized in the conjugate base, then the compound is more acidic compared to the compound whose conjugate base has the charge localized.
• Electronegative substituents or groups like F, Cl, Br, I increase the acidity via inductive electron withdrawal (- I). The closer the substituent is to the carboxyl group, the greater is its effect.
• Electron donating groups such as - OR, -Me, -Et, -NH₂ or –NR,-OH, etc. decrease the acidity via the + R and + I effect.
• Electron withdrawing groups such as NO₂,-CF₃, -COOH, -CN increases the acidity via the – R effect.
• Hydrogen attached to sp Carbon is more acidic than sp² which is again more acidic than carbon attached to sp³ carbon.

Explanation:

• The percentage of 's' character is an sp carbon is 50, in sp² it is 33 and in sp³ it is 25.
• The electron holding or attracting capacity of an 's' orbital is much greater than a 'p' orbital due to the compact shape. So, as s character increases, the electronegativity also increases.
• As carbon attached to the acidic hydrogen becomes more electronegative, it starts attracting the electron density towards itself.
• Hence, the bond between hydrogen and carbon becomes weaker, easier to break, and more acidic easily releasing hydrogen in solution.
• As we move from sp to sp³ hybridization, the electronegativity of the carbon atom decreases, and thus the acidic strength also decreases.

Hence, the acidity order is sp C-H > sp2 C-H > sp3 C-H.

The correct answer is- sp3, sp3d2 and sp3d

Concept:

Hybridization- Hybridization is defined as the concept of mixing of two atomic orbitals to give rise to a new hybridized orbital.

• The atomic orbitals having comparable energies are mixed together in hybridization.
• The new orbital formed has different energy and shape.
• The new orbital formed is known as a hybrid orbital.
• Hybridization happens only during bond formation and not in an isolated gaseous atom.
• The shape of the molecule can be predicted if the hybridization of the molecule is known.

Types of hybridization- Based on the types of orbitals involved in mixing, the hybridization can be classified as -

sp, sp², sp³, sp³d, sp³d², sp³d³

How to calculate Hybridization:

1. Find the valence electrons on an atom whose hybridization is to be determined.
2. Calculate the number of bonded atoms.
3. Calculate the number of lone pairs.
4. Calculate the steric number.
5. On the basis of steric number, the hybridization of an atom can be determined.

Steric Number = No. of atoms bonded + lone pairs of electrons of an atom

Table to determine the hybridization

Explanation:

In H₂O -

• The central atom is O.
• Bonded atoms = H
• Valence electrons of O = 6
• No. of atoms bonded to O = 2
• No. of lone pairs of O in H₂O = 2
• Steric No. of O in H₂O = 4
• Therefore, hybridization of O in H2O = sp³

​In SF₆ -

• The central atom is S.
• Bonded atoms = F
• Valence electrons of S = 6
• No. of atoms bonded to S = 6
• No. of lone pairs of S in SF6 = 0
• Steric No. of S in SF6 = 6
• Therefore, hybridization of S in SF₆ = sp3d²

​In PCl₅ -

• The central atom is P.
• Bonded atoms = Cl
• Valence electrons of P = 5
• No. of atoms bonded to P = 5
• No. of lone pairs of P in PCl5 = 0
• Steric No. of P in PCl5 = 5
• Therefore, hybridization of P in PCl5 = sp3d

Therefore, the hybridization of the central atom in H2O- sp3, SF6 - sp3d2, PCl5 - sp3d

Clemmensen reduction
→ The Clemmensen reduction is a reaction that is used to reduce aldehydes or ketones to alkanes using hydrochloric acid and zinc amalgam. The Clemmensen reduction is named after a Danish chemist, Erik Christian Clemmensen.

Zn(Hg) - conc. HCl is used as a reagent in this reaction.
This reaction is particularly effective in aryl-alkyl ketones reduction formed in Friedel-Crafts acylation. The reaction is more effective in the reduction of cyclic ketones or aliphatic and zinc metals.
Wolff - Kishner reduction-
→ Wolff Kishner's reduction mechanism begins with the formation of a hydrazone anion which then releases the nitrogen atom to form a carbanion.
→ This carbanion then reacts with the water in the system to give a hydrocarbon. Typically, diethylene glycol is used as a solvent for this method.
→ This reduction is an organic reaction where aldehydes and ketones are reduced to alkanes. Some carbonyl compounds are stable in strongly basic conditions, Hence they can be easily reduced to alkanes (The carbon-oxygen double bond becomes two carbon-hydrogen single bonds).

Concept:

Trends of electronegativity:

• A qualitative measure of the ability of an atom in a chemical compound to attract shared electrons to itself is called electronegativity
• Electronegativity increases across a period because of the number of charges on the nucleus increases. That attracts the bonding pair of electrons more strongly.
• Electronegativity decreases across moving down in a group, due to an increase in the distance between the nucleus and the valence electron shell.

Electronegativity decreases down the group and increases from left to right in a period.

The correct answer is Vitamin B₁₂.
Explanation

• Vitamin B₁₂
  • Vitamin B₁₂ is water-soluble, heat-stable, and red in colour.
  • It contains 4.35% cobalt by weight.
  • It contains 63 carbon, 14 nitrogen and, one cobalt atom.
  • Four pyrrole rings coordinated with a cobalt atom is called a corrin ring.

Other Related Points
Vitamin

• Vitamins are organic compounds required by the body in small amounts for metabolism, to protect health, and for proper growth in children. Vitamins also assist in the formation of hormones, blood cells, the nervous system, chemicals, and genetic material.
• They generally act as catalysts, combining with proteins to create metabolically active enzymes that in turn produce hundreds of important chemical reactions throughout the body.
• Without vitamins, many of these reactions would slow down or cease.
• It cannot be synthesized in sufficient quantities by an organism and must be obtained from the diet.

Vitamin B₆

• It is a constituent of a coenzyme involved in amino acid metabolism and assists in the balancing of sodium and potassium.
• It promotes red blood cell production.
• Synthesize serotonin, histamine, and epinephrine.

Vitamin B₂

• Vitamin B₂ is also known as riboflavin, which can find in many plant and animal products.
• It is a water-soluble vitamin. It aids in the metabolism of your fats, carbohydrates, proteins and, ketone bodies.
• It is also important for your energy metabolism.

Vitamin B₁

• Vitamin B₁ or thiamine is a vitamin with energetic functions.
• It nourishes the brain and it's important in cases of forgetfulness, stress, and concentration.

Boiling point-

• A liquid‘s boiling point is the temperature at which its vapor pressure is equal to that of the gas above it. The normal boiling point of a liquid is the temperature at which one atmosphere (760 torrs) is equal to its vapor pressure.
• The boiling point depends on intermolecular hydrogen bonding.
• Thus alcohols tend to have a higher boiling point than ketones because they have an OH group, unlike carbonyls.
• Carboxylic acids have higher boiling points than aldehydes, ketones, and given alcohol of comparable molecular mass.
• This is because of the formation of stronger intermolecular H-bonding than alcohol.

So the correct order of the boiling point is III < II <I.

Concept:
Periodic table:

• It's an arrangement of all the known elements.
• All elements are arranged (from left to right and top to bottom) in order of increasing atomic number and recurring chemical properties.

Explanation
Periods in the Periodic table:

• All the rows represent periods.
• The periodic table has 7 periods.
• Elements in the same period have an increasing order of valence electrons.

Groups in the Periodic table:

• All the columns represent groups.
• Elements in the same group have the same valence electron configuration and therefore same chemical properties.
• The periodic table has 18 groups.

Explanation:

• An increase in nuclear charge pulls the electrons closer to the nucleus.
• The size of the atom reduces in moving from left to right along a period.
• Hence, the atomic radius decreases in moving from left to right along a period.
• Na and K belong to Group I
• Ca and Mg belong to Group II
• The atomic radius of atoms increases from top to bottom within a group, since the atomic number increases down a group.
• Since K is located below Na (in group 1), K has the largest atomic radius.

Correct answer: 1)

Concept:

• Photochemical smog is a brownish-grey haze caused by the action of solar ultraviolet radiation on the atmosphere polluted with hydrocarbons and oxides of nitrogen.
• Sulphurous smog results from a high concentration of sulphur oxides (SOx) in the atmosphere from fossil fuels high in sulphur, such as coal.
• Photochemical smog is the type of smog that refers to peroxyacetyl nitrate (PAN) formation.
• Photochemical smog is brown haze resulting from the reaction of oxides of nitrate with volatile organic compounds (VOC) in the presence of sunlight.
• The major constituents of these hazy fumes are oxides of nitrogen, VOC, ozone (O₃), and PAN. And these hazy fumes (liquid-gas particles) disturb the health of human life and their activities tend to them to reallocate due to poor air quality.

Explanation:

• Smog is a type of air pollution that reduces visibility.
• Smog is the combination of two terms smoke and fog.
• Photochemical smog is formed when the pollutants in the air react with sunlight.
• The sunlight converts the pollutants into chemicals.
• So when sunlight reacts with nitrogen oxide in the atmosphere, smog is produced which is visible as a brown haze, especially during morning and afternoon.
• It can cause health problems like nose and throat infections and severe headaches.
• Brown hazy fumes of photochemical smog are due to nitrogen dioxide

Conclusion:

Thus, the brown, hazy fumes of photochemical smog are due to nitrogen dioxide.

Concept:

pH is a measure of the amount of activity of hydrogen ions (H⁺) in a solution and thus its alkalinity or acidity.

pH is described as “the negative of the logarithm of the molar hydronium-ion concentration.”

The pH Formula can also be noted as pH = – log [H⁺]

Calculation:

The salt here is made from weak base and strong acid. So, the pH formula for this salt is given below:

∵ pK_b = – log K_b

----(1)

Given that,

K_b (NH₄OH) = 10^-5,

Concentration, C = 0.02 = 2 × 10^-2 M

Now,

⇒ -log K_b = – log 10^-5

⇒ -log K_b = 5 log 10

∴ -log K_b = 5

Now,

⇒ log C = log (2 × 10^-2)

⇒ log C = log 2 + log 10^-2

⇒ log C = 0.301 + (-2 log 10)

⇒ log C = 0.301 – 2

∴ log C = - 1.699

Now, substituting the obtained values in equation (1),

Explanation:

• PH₃, ASH₃, NH₃, SbH₃ - these are the hydrides of group 15 elements.
• One thing which is important to note is the hydrides of these elements are basic (Lewis Bases) in nature due to the presence of a lone pair of electrons.
• Because electrons diffuse over a larger volume, basicity decreases with the size of the core atom.
• The M-H bond decreases when the size of central atoms increases. (Where M can be any group 15 element - P, N, As, Bi, Sb)
• As a result, as the size of hydrides grows larger as we move down the group, their stability declines and their decreasing character increases.
• In simple words - The thermal stability of hydrides decreases as we move down the group.
• Hence, the order of their stability is -
  • NH3 > PH3 > AsH3 > SbH3
• Hence, the chemical compound ammonia (NH₃ ) is the most thermally stable.

Concept:

The change in free energy (ΔG) is also a measure of the maximum amount of work that can be performed during a chemical process (ΔG = w_max). ∆G is the change of Gibbs (free) energy for a system and ∆G° is the Gibbs energy change for a system under standard conditions (1 atm, 298K).

The connection between cell potential, Gibbs energy and constant equilibrium are directly related in the following multi-part equation:

∆G⁰ = -nFE⁰_cell

Where, n = number of moles of electrons transferred in the reaction

Calculation:

Given, n = 2

Standard cell potential, E° = 2V

Faraday’s constant, F = 96000 C mol^-1

By substituting these values, we get

∆G0 = -nFE0cell

= - 2(96000) × 2V= - 384000 J/mol

= - 384 kJ/mol

Concept:
Nucleic acids:

• The role of nucleic acids is to see how carbohydrates, proteins, and enzymes originate in the cell and how they preserve their structural formation.
• Nucleic acids are defined as the long-chain polymers present in high concentrations in the nuclei of cells in which the monomeric units are nucleotides.
• The molecules where one of the bases is combined with sugar is called nucleoside.
• When a phosphate group is also attached to the nucleoside, it is called a nucleotide.
• Nucleic acids are responsible for the biosynthesis of proteins and the transmission of hereditary characters.

Explanation:

• There are two types of nucleic acids DNA, RNA.
• DNA molecules are very large and are found in the nucleus of the cell.
• On the other hand, RNA molecules are much smaller and are found outside the cell.
• DNA stands for de-oxy ribonucleic acid. It has a double helix structure.
  
• DNA contains nitrogenous bases, a pentose sugar, and phosphate.
• Two types of nitrogenous bases are there- Purines and pyrimidines.
• The pentose sugar is given below:
  

Hence, in DNA, a pentose sugar is present.
Other Related Points

• The complete hydrolysis of DNA yields β-D-2-deoxyribose, phosphoric acid, and adenine.
• Partial hydrolysis of DNA yields deoxy Adenosine and phosphoric acid.

Concept:

• Naming of compounds containing more than one functional group.
  
• Priority order of functional groups for IUPAC nomenclature.

Explanation:

In the given compound, two functional groups are present
Carboxylic acid (-COOH)
Ketone (-C=O)
Steps used in IUPAC naming of the compound
1. Identify the longest continuous carbon chain.
Here the longest chain has 5 carbon atoms, hence the root name is pent- .
2. Identify the functional group present.
There are two functional groups present, in which the highest priority group is -COOH and the lowest priority group are -C=O.
i.e., -COOH is the suffix and -C=O group is the prefix.
3. Number the carbon atom in such a way that, the highest priority group get the lowest number possible.
Here, the acid group is in C₁ and Keto group is in C_4.

The IUPAC name of the compound is 4-Oxopentanoic acid.

Concept:

• Buffer solution: A buffer solution contains either a weak acid and its salt with a strong base or a weak base and its salt with strong acid. Buffers resist a change in pH when acids or bases are added to them.

• Buffer can be classified into two types;

  • Acidic Buffer: The buffer is formed from the solution of a weak acid and its salt of a strong base. acid. Acidic buffers generally have a pH of less than 7. Example of the acidic buffer is CH3COOH and CH3COONa.

  • Basic Buffer: The buffer is formed from the solution of a weak base and its salt with a strong acid. basic buffers have a pH of more than 7. An example of the basic buffer is NH4OH and NH4Cl.

  • The pH for a buffer solution is given by:

• For buffer solution,

• This equation is known as Henderson - Hasselbalch equation and [ Salt ] is the concentration of the salt in buffer and [ Acid ] is the concentration of the acid in the buffer.
• pK_a is the pK value of acid.
• When the concentration of the acid and the salt are equal, the pH of the buffer solution is equal to the pK_a value of the acid.

Explanation:

• An acetic acid and sodium acetate buffer is an acidic buffer.
• The pH of the buffer is 5.36.
• pK_a of the acid is given which is 4.76.
• From Henderson - Hasselbalch equation, we know,

Substituting the given values, we get:

or,

Hence, [salt] = [acid] as log 1 = 0.

Hence, the ratio, of concentrations of [OAc]/[HOAc] is 1:1.

Important Points

• The buffer is at an equivalent point here.

Concept:
Dehydration reaction of alcohols:

• Alcohols when heated at high temperatures in presence of conc acids, undergoes dehydration.
• They lose a molecule of water and form alkenes.
• The reaction proceeds via a carbocationic intermediate.
• The ease of dehydration follows the order tertiary>secondary>primary.
• There is a formation of unexpected products because the rearrangement of carbocations takes place in the reaction.
• Carbocationic rearrangement takes place whenever there is a possibility of a more stable intermediate to be formed by rearrangement.
• More stable carbonation gives a more saturated alkene as product.

Explanation:

• In the first step, the nucleophilic oxygen of the OH group of alcohol takes up a proton from the acid.
• In the next step elimination of a water molecule takes place and gives the carbocationic intermediate.
• In the third step Re arrangement of this intermediate takes place to give a more stable 3⁰ carbocation.
• Finally, elimination of proton occurs giving more substituted alkenes.

Thus, the major product on dehydration of (CH₃)₃C–CH₂OH is (CH₃)₂C=CH-CH₃.
Mistake Point

• A less stable product from the 3⁰ carbonation can be formed but that is not the major product.
  

Explanation:

Lanthanoid contraction :

→ The cumulative effect of the contraction of the lanthanoid series, known as lanthanoid contraction; Lanthanoid contraction causes the radii of the members of the third transition series to be very similar to those of the corresponding members of the second transition series.

The almost identical radii of Zr (160 pm) and Hf (159 pm) are a consequence of the lanthanoid contraction.

Other Related Points

• The whole periodic table is classified into 4 blocks namely s block, p block, d block, and f block.
• The elements of f blocks are also called inner transition elements.
• 14 elements following Lanthanum are knowns as lanthanoids series and are arranged in a row at the bottom of the periodic table.
• While moving from Lanthanum to Lutecium the atomic radii decreases, these cumulative effects of contraction of lanthanoids series are known as lanthanoids contraction.
• This effect causes the radii of the third transition series to be very much similar to those of corresponding members of the second transition series.
• Hence due to this consequence both these elements occur together thereby making their separation difficult.

Concept:

• The properties that depend on the number of solute particles irrespective of their nature relative to the total number of particles present in the solution are called colligative properties.
• There are four colligative properties: 1. Relative Lowering of vapour Pressure 2. Elevation in Boiling Point 3. Depression in freezing point 4. Osmotic pressure.
• Relative Lowering of vapour Pressure When a non-volatile solute is added to a solvent, the vapour pressure decreases.
• The lowering of vapour pressure w.r.t. the vapour pressure of the pure solvent is called “Relative lowering in vapour pressure”.

Explanation:

Given, P_total= 748 mm

We know that,

From here,

M_A= 145.8 g/mol

Conclusion:

Thus, the molar mass of the liquid is 145.8 g/mol.