Explanation-

The iodine molecules are a class of non-polar molecular solid in which constituents

Molecules are held together by London or dispersion forces. Their solids are soft and non-conductor of electricity.

London forces -

• London dispersion forces are the weakest intermolecular force. London’s dispersion forces can be defined as a temporary attractive force due to the formation of temporary dipoles in a nonpolar molecule.
• When the electrons in two adjacent atoms are displaced in such a way that atoms get some temporary dipoles, they attract each other through the London dispersion force. These intermolecular forces occur between non-polar substances.
• Due to these forces, they can condense to liquids and or freeze into solids at low temperatures.

Ionic bonds-

• Ionic bonds are formed by the formation of cations and anions. An atom forms a cation after losing of electron and such ions have a positive charge. If an atom accepts electrons, it results in the formation of an anion that has a negative charge. Cation and anion attract each other to form an ionic bond. So we can say that ionic bonds are an electrostatic force of attraction between oppositely charged ions.

Covalent bonds-

• The sharing of electrons helps to get the octet configuration to both bonded atoms. Covalent bonds are usually formed between two non-metals. They can be polar or nonpolar in nature. The polarity of covalent bonds depends on the electronegativity of both bonded atoms. 

Explanation:

Amorphous solid-

• An amorphous solid is that in which the constituent particles do not possess a regular three-dimensional arrangement.
• Amorphous solids, lacking the three-dimensional long-range order of a crystalline material, possess a more random arrangement of molecules, exhibit short-range order over a few molecular dimensions, and have physical properties quite different from those of their corresponding crystalline states.

Properties-

They are rigid and incompressible.

1. Lack of long-range order-

⇒ Amorphous Solid does not have a long-range order of arrangement of their constituent particles.

⇒ However, they may possess small regions of orderly arrangement.

⇒ These crystalline parts of an otherwise amorphous solid are known as crystallites.

2. No sharp melting point-

⇒ An amorphous solid does not have a sharp melting point but melts over a range of temperatures.

⇒ For example, glass on heating first softens and then melts over a temperature range. Glass, therefore, can be molded or blown into various shapes. Amorphous solid does not possess the characteristic heat of fusion.

3. Conversion into crystalline form-

⇒ Amorphous solid, when heated and then cooled slowly by annealing, becomes crystalline at some temperature.

⇒ That is why glass objects of ancient times look milky because of some crystallization having taken place.

4. Isotropic-

⇒ Amorphous solids are isotropic. That is, they exhibit uniform properties in all directions.

⇒ The thermal and electrical conductivities, coefficient of thermal expansion, and refractive index of an amorphous solid have the same value in whatever direction the properties are measured.

So option 2 is the correct answer.

Concept:

• Atoms at the edge of a unit cell:
  • ​In a crystal lattice, an edge of a unit cell is shared by four other unit cells.
  • One is the adjacent unit cell and the other two are on the layer just above the unit cell.
  • So each edge contributes to one-fourth of an atom in a unit cell.
  • There are 12 edges per unit cell, thus a total number of atoms becomes 12 × 1/4 = 3.

​

• Atoms at the corners of a unit cell:
  • The corner atoms are shared via 8 cubes, so the contribution from each corner is 1/8.
  • Total number of atoms on the corner of a cube = 8
  • The total number of atoms from corners is 8 × 1/8 = 1.
• Atoms at the face of a unit cell:
  • ​Each face is shared by two unit cells.
  • the contribution from each face is thus 1/2.
  • There are six faces in a cube, so the total contribution from the faces of the cube = 3​

Calculation:

• The atoms present at the corners are X.
• Contribution from all the corners = 1.

So, the total number of X atoms = 1.

• Y atoms are present at the edges.
• Total number of atoms at edges = 3,

So the number of Y atoms = 3.

• The total contribution from all 6 faces is 3.
• Z atoms are present at the faces.

So total number of Z atoms = 3.

Hence, the formula of the compound is XY₃Z₃.

Calculation:

For Fcc, the rank of the unit cell (Z) = 4

Mass of one Cu-atom, M - 63.55 u

Avogadro’s number, N_A = 6.023 × 10²³ atom

Edge length, $a$ = x Å = x × 10^-8cm

Density, $\left(\mathrm{d}\right)=\frac{Z\times M}{N_A\times a^3}$

$=\frac{4\times 63.55}{6.023\times {10}^{23}\times {\left(x\times {10}^{-8}\right)}^3}$

$=\frac{422.048}{x^3}gc{m}^{-3}$

Explanation-

Normality-

→ Normality is described as the number of gram or mole equivalents of solute present in one liter of a solution.

→ The equation of normality that helps to estimate the volume of a solution required to prepare a solution of different normality is given by,

→ Initial Normality (N₁) × Initial Volume (V₁) = Normality of the Final Solution (N₂) × Final Volume (V₂)

→ Suppose four different solutions with the same solute of normality and volume are mixed; therefore, the resultant normality is given by;

→ N_R = [N_aV_a + N_bV_b + N_cV_c + N_dV_d] × [V_a + V_b + V_c + V_d]^-1

Given data and Calculation-

→ N₁ = N,  V₁ = 5 mL

→ N2 = N/2,  V2 = 20 mL

→ N₂ = N/3,  V₃ = 30 mL

→ NV = N₁V₁ + N₂V₂ + N₃V₃

→ N × 1000 = (1 × 5) + (0.5 × 20) + (0.33 × 30)

→ N = 0.025N = N/40

Concept:

Abnormal Colligative properties:

• The colligative properties of solutions were determined by assuming that the solutes are neither associating or dissociating.
• However, in experiments, it is seen that the results do not match with the theoretical values.
• This can be attributed to the fact that some solutes associate whereas some dissociate when dissolved in water.
• KCl, when dissolved in water shows an increase in the theoretical or calculated value of the increase in boiling point.
• This is because KCl as an electrolyte dissociates in solution and its observed mass is lower than the calculated value.
• When acetic acid is dissolved in benzene, it undergoes dimerization due to hydrogen bonding.
• Thus, the number of solute particles decreases, and hence the observed value also decreases.
• There occurs changes in colligative properties when there is dissociation or association of the solute molecules.
• The abnormal changes also depend upon the degree of association or dissociation.
• In 1980, vant Hoff introduced factor 'i', which is the ratio of the measured colligative properties by calculated colligative properties, denoted by 'i'.

Explanation:

• The colligative properties depend on the number of particles in the solution.
• When dissociation of solutes, occurs, the number of particles increases and the deviation from calculated values also increases.
• The experimental value is much higher than the calculated value.
• When association occurs, the number of solute particles decreases and the experimental values are much less than the calculated values. 
• Thus, the value of vant Hoff factor also depends upon the number of particles in the solution.
• The larger the number of solute particles or ions, the greater will be the value of vant Hoff factor 'i'.
• Ca(NO3)2 dissociates to produce one ion of Ca²⁺ and two ions of NO₃^-, the total number of ions produced are three.

Ca(NO3)2 →  Ca2+ + 2NO3-

• K3[Fe(CN)6] dissociates to give 3K⁺ and [Fe(CN)6]^- ion. In total, four ions are produced.

K3[Fe(CN)6] → 3K+ + [Fe(CN)6]-

• K2SO4 dissociates to produce 2K⁺ and one SO₄^_ ion. The total number of ions produced in the solution is three.

K2SO4  → 2K+ + SO4^-

• Al2(SO₄)3 dissociates to produce 2Al³+ and four SO4^-i on. The total number of ions produced is five.

Al2(SO4)3  → 2Al3+ + 4SO4-

• Al2(SO4)3 dissociates in solution to produce the highest number of ions which is five.

Hence, Al2(SO4)3 has the highest value of vant Hoff factor.

Explanation:

Given,

Strength = 10 %, 

Volume in 1 g mole = ?

→ 10 % glucose strength means, in 100 g of solution 10 g is glucose and 90 g is water:

∴ Number of moles of glucose = (10 g)/(180 g/mole) = 1/18 mole.

So, 1/18 mole of glucose is dissolved in 0.1 L solution

∴ One gram mole of glucose is dissolved in = 0.1 × 180/10 = 1.8 L

Explanation:

When the attractive forces between molecules of a liquid are large, the surface tension is large. 

Surface tension depends mainly upon the forces of attraction between the particles within the given liquid and also upon the gas, solid, or liquid in contact with it. 

Now let's see why other statements are correct

→ The boiling point is called normal at 1atm pressure and the standard boiling point is called when the pressure is at 1bar pressure.

1bar pressure is slightly less than 1 atm pressure, so the Standard boiling point of a liquid is slightly lower than the normal boiling point.

→ Boiling will take place only when the pressure of the liquid is equal to atmospheric pressure.

And hence in the closed vessel, the pressure will be more than that of the atmosphere and boiling will not occur.

→ The SI physical unit of coefficient of viscosity is the Pascal-second (Pa s), which is identical to kg m⁻¹ s⁻¹.

Explanation-

• The amount of mass liberated at the electrode is directly proportional to the quantity of the current passed into the solution.
• The amount of metal deposited depends on the nature of the metal, the amount of current used in electrolysis, and the duration for which electrolysis was performed.
• The relation between the number of moles of electrons and the charge is as follows.

Number of moles of electrons = Q/F

Here Q = Charge, F = Faraday = 96500 C

Charge (in F) = moles of e⁻ used = moles of Na deposited 

Given data and Calculation-

→ Mass of Na deposited = 11.5 g

→ Moles of Na deposited = $\frac{11.5}{23}$ = 0.5 moles

→ Charge = 0.5 F

Explanation:

The Reaction at the Anode and cathode is,

Anode:- Mg →  Mg²⁺ + 2^e

Cathode:- Cl₂ + 2^e  →  2Cl^-

1. The left side half cell is the anode (oxidation)

2. The right side half cell is the cathode (reduction)

Combining the equation we get,

⇒ Mg + Cl₂ →  Mg²⁺ + 2Cl^-

Now by putting it in the form of the Nernst equation we get,

$E_{cell}=E_{cell}^{\circ }-\frac{RT}{nf}ln\frac{[M{g}^{2^{+}}][C{l}^{-}{]}^2}{[Mg][C{l}_2]}$ (or) $E_{cell}=E_{cell}^{\circ }-\frac{0.0592}{n}log\frac{[M{g}^{2^{+}}][C{l}^{-}{]}^2}{[Mg][C{l}_2]}$

As Mg and Cl₂ are in their pure state, let's consider their concentration,

⇒ [Mg] = [Cl₂] = 1

So $E_{cell}=E_{cell}^{\circ }-\frac{RT}{nf}ln[M{g}^{2^{+}}][C{l}^{-}{]}^2$  (or)  $E_{cell}=E_{cell}^{\circ }-\frac{0.0592}{n}log[M{g}^{2^{+}}][C{l}^{-}{]}^2$

Hence the correct option is 3

Explanation-

The SI unit of conductance is siemens, represented by the symbol ‘S’ and is equal to ohm^–1 (also known as mho) or Ω ^–1. The inverse of resistivity, called conductivity (specific conductance) is represented by the symbol, κ (Greek, kappa).

The conductivity of electrolytic (ionic) solutions depends on: 

• The nature of the electrolyte added 
• Size of the ions produced and their solvation 
• The nature of the solvent and its viscosity 
• Concentration of the electrolyte 
• Temperature (it increases with the increase of temperature)

So option 3 is incorrect as Conductivity depends upon solvation of ions present in solution.

Explanation-

Order of reaction-

• The order is the sum of the powers to which the concentration of reactants is raised in a rate law expression.
• The rate of the reaction aA + bB → cC is rate = [A]^x + [B]^y where an order is x + y.
• On varying the concentration of any of the reactants, the rate of the reaction also changes.
• There are different orders for different reactions. It can be zero order, first order, second order, pseudo-first-order, etc
• The exponent on each concentration term is the order of the reaction in that particular reactant.
• Since it is experimentally determined., it can be integers or fractions.
• It is not affected by the stoichiometric coefficient of the reactants.

Explanation:

⇒ First-order rate equation is - $k=\frac{2.303}{t}\log \frac{{[R]}_0}{[R]}$ .

⇒ The sum of powers of the concentration of reactants in the rate law expression is called the order of that chemical reaction.

⇒ First-order reaction - The rate of reaction is proportional to the first power of the concentration of reactants, which means that the rate of reaction is directly proportional to the concentration of reactants.

Given,

Reaction rate (k) = 10^-2 sec^-1

a = 20 g, a - x = 5 g

$t=\frac{2.303}{k}\log \left(\frac{a}{a-x}\right)$

$t=\frac{2.203}{{10}^{-2}}\log \left(\frac{20g}{5g}\right)$

t = 138.6 sec

Explanation-

Activation energy-

• Activation energy is defined as the minimum amount of extra energy required by a reacting molecule to get converted into a product.
• It can also be described as the minimum amount of energy needed to activate or energize molecules or atoms so that they can undergo a chemical reaction or transformation.
• For an endothermic reaction,

​

• (E_a)_f > (E_a)_b
• (ROR)_f < (ROR)_b
• $\mathrm{\Delta }H=$ (E_a)f - (E_a)b
• △H = +ve value

Given data and Calculation-

From the graph, E_a = 150 KJ

△H = +100 KJ

(Ea)b = 150 - 100 = 50 KJ

Ea for the reverse reaction will be 50 KJ.

Explanation-

Collision Theory-

• According to the collision theory, “the molecules of reactants are assumed to be hard spheres and the reactions are assumed to occur only when these spheres (molecules) collide with each other”.
• So it was important to quantify the number of collisions occurring in order to form products so that we can have a clear picture of the reaction, and hence came the term collision frequency.
• The activation energy and proper orientation of the reacting molecules together determine the condition for a collision that will result in the formation of products that is an effective collision.
• So in collision theory, both activation energy and effective collision govern the rate of a reaction.
• As per the Arrhenius Equation, all the molecules that have energy greater than or equal to activation energy will collide to form products. But this postulate was not true for all the reactions.
• The collisions having energy higher than the threshold value give a successful reaction.

Explanation:

⇒ When an excess of electrolyte is added to the colloid it neutralizes the charge present on the colloidal particles due to which the colloidal solution coagulates.

Important Points 

• The addition of an electrolyte in a solution causes coagulation as a result of the preferential adsorption of the ions of charge opposite to that on the colloidal particle.
• This preferential adsorption lowers the zeta potential to some critical value, and coagulation takes place.

Additional Information

Electrolyte

• It is a substance that produces an electrically conducting solution when dissolved in a polar solvent, like water.
• The dissolved electrolyte separates into anions and cations, which disperse uniformly through the solvent.
• Electrically, this type of solution is neutral.
• Electrolyte replacement is needed when a person has prolonged diarrhea or vomiting.

Explanation:

⇒ Coagulation power ∝ 1/Coagulation Value

Given,

I. (NaCl) = 52

II. (BaCl2) = 0.69

III, (MgSO4) = 0.22

Coagulation Value of NaCl > BaCl₂ > MgSO₄ 

∴ Coagulation Power is MgSO4 > BaCl2 > NaCl 

Explanation: 

• In adsorption isotherms, the fraction of moles of adsorbate (x) by the grams of adsorbent(m) versus P is plotted.
• The Freundlich isotherm gives us the empirical relationship between the amount of gas adsorbed and its equilibrium pressure P.
• It is seen that the amount of adsorption increases with an increase of pressure when the pressure is in the lower range.
• As the pressure increases, the rate of adsorption increases but reaches saturation after some point.
• After this point, the amount of adsorption doesn't change even when pressure is increased.

The equation of the Freundlich isotherm is given as follows:

→  $\frac{\mathrm{x}}{\mathrm{m}}\propto {\mathrm{P}}^{\frac{1}{\mathrm{n}}}$

Where k and n are constant for a particular adsorbent and adsorbate at a fixed temperature.

→ The graph is represented as follows.

When the temperature is fixed and pressure is low, the adsorption becomes directly proportional to the pressure of the gas.

→ The relation reduces to

→ x = kP.

This signifies, 1/n = 1 or n = 1.

→ At a higher range of pressure, the adsorption becomes independent of pressure and the equation reduces to

→ x/m = k.

We can infer from this that 1/n = 0.

→ Hence, in Freundlich adsorption isotherm, the value of 1/n is 0 to 1.

Explanation:

Option 1

⇒ O₃ + SO₂ → O₂ + SO₃ hence correct.

Option 2

⇒ Si + 2NaOH +O₂ →  NA₂SiO₃ + H₂O hence correct statement

Option 3

Cl₂ reacts with an excess of ammonia to produce ammonium chloride and nitrogen

2NH₃ + 3Cl₂ → N₂ +6HCl

6NH₃ + 6HCl → 6NH₄Cl

8NH₃ + 3Cl₂ → N₂ + 6NH₄Cl hence correct statement

Option 4

⇒ 3Br₂ + 6NaOH → 5NaBr + NaBrO₃ +3H₂O  hence incorrect statement

Explanation-

Oxidizing agent-

• An oxidizing agent is a compound or element that participates in a redox (oxidation-reduction) reaction and accepts electrons from a different species.
• An oxidant is a chemical compound that easily transfers oxygen or another substance atoms in order to gain an electron.

Reducing agent-

• A substance that loses electrons to other substances in a redox reaction and gets oxidized to a higher valency state is called a reducing agent.

Given data and Analysis-

• HI cannot be prepared by the action of conc. H_2​SO_4​ on KI because H₂​SO₄​ is an oxidizing agent and HI is a strong reducing agent.
• HI reduces sulphuric acid to sulphur dioxide and itself is oxidized to iodine.
• KI + H₂​SO_4​ → KHSO₄​ + HI
• H_2​SO_4​ + 2HI → SO₂​ + I₂ ​+ 2H₂​O
• Hence, HI is prepared by heating KI with conc. phosphoric acid.  The same is true for the preparation of HBr.

Explanation-

• KMnO₄ is a powerful oxidizing agent in a neutral, alkaline, and acidic medium.
• So, in an acidic solution, potassium permanganate can oxidize chloride ions to chlorine gas.
• Chlorine gas can be prepared by the action of concentrated HCl and KMnO_4.
• $$\begin{gathered} \frac{2\mathrm{K}\mathrm{M}\mathrm{n}{\mathrm{O}}_4+6\mathrm{H}\mathrm{C}\mathrm{l}\to 2\mathrm{K}\mathrm{C}\mathrm{l}+2\mathrm{M}\mathrm{n}\mathrm{C}{\mathrm{l}}_2+3{\mathrm{H}}_2\mathrm{O}+5[\mathrm{O}] \\ [2\mathrm{H}\mathrm{C}\mathrm{l}+[\mathrm{O}]\to {\mathrm{H}}_2\mathrm{O}+\mathrm{C}{\mathrm{l}}_2]\times 5}{2\mathrm{K}\mathrm{M}\mathrm{n}{\mathrm{O}}_4+16\mathrm{H}\mathrm{C}\mathrm{l}\to 2\mathrm{K}\mathrm{C}\mathrm{l}+2\mathrm{M}\mathrm{n}\mathrm{C}{\mathrm{l}}_2+5\mathrm{C}{\mathrm{l}}_2+8{\mathrm{H}}_2\mathrm{O}} \end{gathered}$$
• Chlorine gas evolved by this process contains impurities of HCl and water vapor.
• It can be purified by bubbling through water and concentrated H₂SO₄. Water absorbs the traces of HCl and concentrated H₂SO₄ absorbs moisture. The Cl₂ thus obtained is collected by the upward displacement of air.
• This method is generally used in the laboratory to prepare Cl₂. Chlorine is the most abundant element in the halogen family. It was discovered by Scheele in 1774. He prepared it by heating HCl and MnO2 then gave the name oxymuriatic acid.
• So chlorine is prepared by both MnO2 and KMnO4.

Explanation-

Ammonia is a colorless gas with the chemical formula NH₃.

The structure of Ammonia is

  .

• Ammonia is known to behave as a weak base since it combines with many acids to form salts.
• For example, when it is reacted with hydrochloric acid, ammonia is converted into ammonium chloride.
• All the salts that are produced from such acid-base reactions are known to contain the ammonium cation, denoted by NH₄⁺.
• In an acidic solution, N atoms of NH₃ donate their lone pair electrons to protons forming NH₄⁺ ions.
• Therefore, lone pair electrons of NH₃ are not available for forming the complex with copper ions.

Explanation-

The full name of EDTA is ethylene diamine tetraacetic acid. The structure of EDTA is shown below:

• EDTA contains six donor atoms. These include two nitrogen atoms and 4 oxygen atoms. Thus, EDTA is a hexadentate ligand.
• When EDTA solution is added to Mg²⁺ ion solution, the following reaction takes place-
• Mg²⁺  + [H₂EDTA]²⁻→ [Mg(EDTA)]²⁻ + 2H⁺ 
• Four coordinate sites of Mg²⁺ are occupied by forming bonds with four oxygen atoms of EDTA and the remaining two sites are occupied by forming bonds with two nitrogen atoms of EDTA.
• Thus, all six-coordinate sites of Mg²⁺are occupied.
• When EDTA reacts with  Mg²⁺ ions, it produces protons. This increases the hydrogen ion concentration and decreases the pH of the solution
• The colorless [Mg - EDTA]²⁻ complex is formed during the reaction.

So statement given in option 1 is not true.

Explanation:

Given,

⇒ CFSE for Octahedral (Δ _o) = 18,000 cm^-1

⇒ CFSE for Tetrahedral (Δ _t) = (x) ×102 cm–1

⇒ The relation between these is  ${\Delta }_t=\frac{4}{9}{\Delta }_0$

Δ t = (4/9) × 18,000 cm-1

Δ t = 8,000 cm–1 = 80 × 102 cm–1 

∴ x = 80

Explanation:

To know the conductivity of the solution we will need the ratio of electrolytes present.

Given

⇒ 0.1 mol CoCl₃(NH₃)₅ + AgNO₃ → 0.2 mol AgCl

Suppose

⇒ 1 mol AgNo₃ + 1 mol Cl^- →  1 mol AgCl + No₃^- 

⇒ means 1 mol of AgNo₃ reacts with 1 mol Cl^- to give 1 mol AgCl similarly if we take 0.1 or 0.2 mol we will get AgCl in particular moles.

⇒ So the complex will need 0.2 mol of chloride ion to give 0.2 mol AgCl

$[Co(N{H}_3{)}_{5}Cl]C{l}_2+AgN{O}_3\to 2AgCl+2N{O}_3^{-}$

⇒ So the ratio should be [Co(NH₃)₅Cl]⁺² 2Cl^-  which will be 1:2

Explanation:

The formula of hypophosphorous acid is H₃PO₂, It is a monobasic acid.

Additional InformationFew Other Figures.

1. HNO₃ 

2. H₄P₂O₇

3. H₃PO₃

Explanation:

⇒ Ostwald process for the manufacture of nitric acid:

$\underset{Ammonia}{4N{H}_3}+5O_2$ $\underset{700-{800}^{0}C}{\overset{Ptgauge}{\to }}$ $\underset{Nitricoxide}{4NO}+6H_{2}O$; $\mathrm{△}$H = -21.5 kcal

$2NO+O_2$ $\stackrel{{50}^{0}C}{\to }$ $\underset{Nitrogendioxide}{2N{O}_2}$

$4N{O}_2+2H_{2}O+O_2\to \underset{Nitricacid}{4HN{O}_3}$

Explanation:

→ Ozone protects the earth's inhabitants by absorbing UV radiation.  (Option D is incorrect)
→ Ozone is diamagnetic whereas dioxygen is paramagnetic. 
→ Ozone being unstable is more reactive than stable dioxygen.
→ Ozone is formed in the upper atmosphere by a photochemical reaction involving dioxygen.

Explanation:

→ C + 2 H₂SO₄ → CO₂ + 2 SO₂ + 2 H₂O

→ Carbon (C) is the elements oxidized by conc. H₂SO₄ to give two gaseous products which are CO₂ & SO₂

Explanation:

⇒ The SN² reaction is a nucleophilic substitution reaction where a bond is broken and another is formed synchronously. Two reacting species are involved in the rate-determining step of the reaction.

SN² reaction reactivity order is less steric hindrance means less the hindrance more reactive is the compound.

⇒ In SN¹ reaction formation of carbocation happens so 3° carbocation is more stable than 2° & 2° carbocation is more stable than 1° .(3° >2° >1° ) but in SN² reaction it is vice-versa 1° > 2° > 3° if leaving group is same. also, the substituents attached which are smaller in size than the compound will be more reactive.

⇒ In all the options leaving the group is the same ie. Cl so let's check the degree of the carbon to which halogen is attached.

1) 

2) 

3) 

4) 

So option 3 will undergo SN² reaction faster.

Explanation:

⇒ -NO₂  group is an electron-withdrawing group and it decreases electron density at ortho and para positions.

→ So a nucleophile is attracted to a more electron-deficient substrate and hence nucleophilic substitution becomes easier and hence the replacement of Cl is easier.

NO2 withdraws e- from ortho/para positions.

Explanation-

NBS-

N-Bromosuccinimide (NBS) is a brominating and oxidizing agent that is used as a source of bromine in radical reactions (for example- allylic brominations) and various electrophilic additions.

Given Reaction-

It will follow the free radical mechanism.

Formation of radical-

Shifting of electron-

The electron will shift as shown below-

Reaction with Bromine-

So the final product will be as shown above.

Explanation:

Acetyl bromide reacts with an excess of  CH3Mgl followed by treatment with a saturated solution of NH4Cl giving tertiary alcohol which in the given option

is: 2-methyl-2-propanol.

Explanation:

Pyridinium chlorochromate (PCC), a complex of chromium trioxide with pyridine and HCl gives a good yield of aldehydes and prevents further oxidation to carboxylic acids.

→ CH₃CH₂OH   $\stackrel{PCC}{\to }$  CH₃CHO

Additional Information→ PCC = Pyridinium chlorochromate (C5H5NHClCrO3) is used for the oxidation reaction of aldehydes, alcohols, and ketones. 

Explanation:-

The reaction of Phenol with NH₃:

• Treatment of aniline with nitrous acid (NaNO₂ and HCl) at ice-cold temperatures produces benzene diazonium chloride.
• The phenol is then formed by hydrolysis with dilute sulphuric acid.
• Aniline is formed when phenol reacts with ammonia.
• The -OH group is replaced by the -NH₂ group in this reaction.
• To begin, treat phenol with zinc dust and a small amount of heat to convert it to benzene.
• Then treat benzene with nitric acid and dilute sulphuric acid (a process known as nitration) to produce nitrobenzene, which is then treated with an active metal and an acid.
• We've gotten Aniline.

Reaction:

Explanation:-

Reimer–Tiemann reaction:

• The Reimer–Tiemann reaction is a chemical reaction that is used to ortho-formylate phenols, with the conversion of phenol to salicylaldehyde being the most basic example.
• Karl Reimer and Ferdinand Tiemann were the first to discover the response.
• It was Karl Reimer, not the lesser-known Reimer, who was in dispute. Reimer, Carl Ludwig
• The Reimer Tiemann reaction is an organic chemical reaction in which chloroform, a base, and an acid workup are used to convert phenol into an ortho hydroxy benzaldehyde.
• The chemical reaction for ortho-formylation of phenols can also be characterised as this reaction.
• The Reimer-Tiemann reaction is performed on phenols in the presence of chloroform, and the end product is an aldehyde.

Reaction:

Option A is Correct according to the reaction. 

Explanation:

Intermolecular hydrogen bonding is present in alcohols and not in ethers. Therefore, ethers have less boiling points and are more volatile than alcohols.

Explanation:

Three membered epoxide ring has ring strain. So, on reaction with a nucleophile, on less hindered carbon. It cleaves the epoxide ring and then the negative oxygen atom attacks to substitute chlorine because chlorine is a good leaving group.

Concept:

• Benedict's test is an alkaline solution of complex cupric nitrate.
• Aldehydes get oxidized to acids and the indication is a red ppt of Cu2O.

Fehling's test:

• It is an alkaline solution of CuSO4 and sodium-potassium tartrate.
• The aldehydes reduce Cu2+ to red cuprous oxide.

Schiff's reagent:

• A colorless solution of Schiff's base when reacted with aldehydes, it turns magenta colored.

Grignard Reagent:

• The Grignard reagent is given as RMgX where X is a halogen, and R is an alkyl or aryl (based on a benzene ring) group.
• They react with both aldehydes and ketones to form addition products. 

Explanation:

• Acetaldehyde and ketones both are oxidized to acids upon subjected to oxidizing agents.
• Aldehydes are much easier to oxidize than ketones and therefore weak oxidizing agents like Schiff's reagent, Tollen's, and Fehling's are not able to oxidise ketones.
• The carbonyl carbon in the aldehydes and ketones is a nucleophilic center.
• The carbon center in the Grignard reagent is a nucleophile. The carbon attacks the carbonyl carbon and forms an adduct.

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Thus the reagent with which both acetaldehyde and acetone react easily is Grignard Reagent.

Explanation:

Option 1

→ Cannizzaro reaction is a chemical reaction named after Stanislao Cannizzaro that involves the base-induced disproportionation of two molecules of a non-enolizable aldehyde to yield a carboxylic acid and a primary alcohol.

Option 2

→ A proton is exchanged by acid and alkoxide ions. When a base of high concentration is introduced, the aldehyde forms an anion which has a charge of 2. From this, a hydride ion is transferred to a second molecule of the aldehyde, forming carboxylate and alkoxide ions. The alkoxide ion also obtains a proton from the solvent for the reaction.

Option 3

→ Cannizzaro's reaction is not given by all the carbonyl compounds.

Option 4

→ A 50% aqueous or ethanolic solution is generally used in the Cannizaro reaction as it is used for aldehydes that do not have α-H. 

Explanation:

→ In presence of organic peroxide, the halogen adds with the carbon in a double bond has a greater number of the hydrogen atoms.(antimarkovnikov addition)

→ Anti Markovnikov rule describes that in addition to reactions of alkenes or alkynes, the proton is added to the carbon atom that has the least number of hydrogen atoms attached to it.

→ The Anti Markovnikov rule works against the Markovnikov rule and is called as peroxide effect or Kharasch effect.

→ CH₂=CH(CH₂)₂COOH +HBr $\stackrel{peroxide}{\to }$ BrCH2CH2(CH2)2COOH

Explanation:

→ Bond length is a measure of the distance between the nuclei of two chemically bonded atoms in a molecule.

→ It is approximately equal to the sum of the covalent radii of the two bonded atoms.

→ C = O bond length is shorter than C - O bond length.

Explanation:

→ When acid anhydrides react with primary amine

Hence option 1 is correct

Explanation:

→ Quaternary ammonium salts are positively charged polyatomic ions of the structure NR4⁺X⁻, where R is an alkyl group or an aryl group and X is an anion(usually the halide ion). The quaternary ammonium cations are permanently charged.

→ Hence C₃H₉N will not represent quaternary ammonium salt as it does not have a halide ion as well as no charge with N.

C₃H₉N will represent,

Concept:

Grignard Reagent:

• The Grignard reagent is given as RMgX where X is a halogen, and R is an alkyl or aryl (based on a benzene ring) group.
• They react with a variety of compounds such as acids, aldehydes, ketones, alkynes to form addition products.
• Grignard reagent usually attacks the nucleophilic center.
• The polarity of Grignard reagents is opposite to that expected because here the carbon atom bears a negative charge and acts as nucleophiles.
• This effect is called the Umpolang Effect or reversal of polarity.

• Methyl magnesium bromide is CH3MgX and falls in the category of Grignard Reagents.
• The methyl group bears a partial negative charge and the metal bears a partial positive charge.

Explanation:

• Primary and secondary amines react with Grignard reagents to form alkanes.
• For the reaction to occur, there have to be hydrogen atoms attached to the nitrogen atom.
• The hydrogen is extracted by the negatively charged alkyl group of the Grignard reagents leading to the formation of alkanes.
• As there are no hydrogens attached to the Nitrogen atom of tertiary amines, they do not undergo the reaction with Grignard reagents.
• The reaction of ethylamine with methyl magnesium bromide, Methane is formed from the alkyl part of the Grignard Reagent.
• The reaction can be written as:

• When ethyl amine will be treated with ethyl magnesium bromide, it will give ethane. The reaction will be:

C₂H₅NH₂ + C₂H₅MgBr → C₂H₆

Hence, when ethylamine is treated with methyl magnesium bromide, the product formed is methane.

Mistake Points 

• Ethylamine when treated with NaNO₂ + HCl, gives ethyl alcohol as the product.

• Similarly, methylamine will yield methanol.

Explanation:

Option 1

⇒ Yes, both the structures of glucose form pentaacetate as they have 5 OH groups, but the question is not correct because in both reactions pentaacetate is formed.

Option 2

⇒ To react with hydroxylamine CO group should be present which is present with the glucose noncyclic and forms oxime but not with cyclic structure.

Option 3

⇒ Pentacetate of glucose will react with hydroxylamine to form an oxime in a non-cyclic structure but glucose will not react with hydroxylamine in a cyclic structure, hence this is the rection of glucose can only be explained in a cyclic structure.

Option 4

⇒ This statement is correct only with non-cyclic structures but not with cyclic structures.

The correct answer is Zymase.

Key Points

• Zymase
  • Zymase enzyme can catalyse the conversion of glucose to ethanol.
  • Zymase is an enzyme complex that catalyzes the fermentation of sugar into ethanol and carbon dioxide.
  • It occurs naturally in yeasts.
  • Glucose undergoes fermentation and catalyzes the conversion of glucose to ethanol in the presence of enzymes, found in yeasts.
  • C6H12O6 - In the presence of Zymase - 2C2H5OH + 2CO2.

Additional Information

• Invertase - Invertase is an enzyme that catalyzes the hydrolysis (breakdown) of sucrose (table sugar) into fructose and glucose.
• Maltase - Maltase, enzyme that catalyzes the hydrolysis of the disaccharide maltose to the simple sugar glucose. 
• Diastase - Diastase is a general term for enzymes that hydrolyze starch and glycogen.

Explanation:

Option 1

• Insulin helps keep the glucose in your blood within a normal range. It does this by taking glucose out of your bloodstream and moving it into cells throughout your body. The cells then use the glucose for energy and store the excess in your liver, muscles, and fat tissue.

Option 2

• Ovalbumin is the predominant protein in albumen and represents 54% to 58% of the egg white protein by weight. 

Option 3

• Prothrombin is transformed into thrombin by a clotting factor known as factor X or prothrombinase, thrombin then acts to transform fibrinogen, also present in plasma, into fibrin, which, in combination with platelets from the blood, forms a clot (a process called coagulation).

Option 4

• Denaturation makes the proteins less active. Due to denaturation, proteins lose their biological activity.

Hence option 4 is an incorrect statement.

The correct answer is 1, 2 and 3 only.

Key Points

• Terylene
  • It is a synthetic polyester fibre produced by polymerizing ethylene glycol and terephthalic acid which is obtained from petroleum.
  • The fibre was first created in 1941 by chemist J R WINFIELD of Accrington who sold the patent rights to the chemical company ICI.
• Teflon
  • It is a brand name for a synthetic chemical called polytetrafluoroethylene (PTFE).
  • It was first made in 1938 by Roy J. Plunkett to create a non-reactive, nonstick surface.
  • It’s known for its use in cookware, although it can also be used to coat other materials like wires or fabrics to make them waterproof. 
  • It is a suspected carcinogen, hormone disruptor, and reproductive toxin.
• Melamine formaldehyde
  • It is a hard, very durable, and versatile thermosetting aminoplast with good fire and heat resistance.
  • It is made from melamine and formaldehyde by condensation of the two monomers.
  • Its good fire retardant properties are due to the release of nitrogen gas when burned or charred.
• Nylon 6 or polycaprolactam
  • It is a polymer developed by Paul Schlack at IG Farben to reproduce the properties of nylon 6,6 without violating the patent on its production.
  • It is a semicrystalline polyamide.
• Hence, Option 2 is correct.

The correct answer is 2 only.

Key Points

• Tranquillizers and analgesics are neurologically active drugs. Hence, Statement 2 is incorrect.
• These affect the message transfer mechanism from the nerve to the receptor.
• Tranquillizers are a class of chemical compounds used for the treatment of stress and mild or even severe mental diseases. 
• These relieve anxiety, stress, irritability or excitement by inducing a sense of well-being. Hence, Statement 1 is correct.
• They form an essential component of sleeping pills.
• There are various types of tranquillizers.
• They function by different mechanisms.
• For example, noradrenaline is one of the neurotransmitters that play a role in mood changes.
• If the level of noradrenaline is low for some reason, then the signal-sending activity becomes low, and the person suffers from depression.
  • In such situations, antidepressant drugs are required.
  • These drugs inhibit the enzymes which catalyse the degradation of noradrenaline.
• If the enzyme is inhibited, this important neurotransmitter is slowly metabolised and can activate its receptor for longer periods of time, thus counteracting the effect of depression.
  • Iproniazid and phenelzine are two such drugs.
• Some tranquillizers namely, chlordiazepoxide and meprobamate, are relatively mild tranquillizers suitable for relieving tension.
• Equanil is used in controlling depression and hypertension.