SRMJEEE Chemistry Mock Test - 4 - JEE MCQ

To determine the identity of compound 'X', consider the following:

• Compound 'X' reacts with acidified K₂Cr₂O₇, indicating it likely contains a functional group that can be oxidised.
• Compound 'Y' can react with I₂ and sodium carbonate to produce triodomethane, suggesting 'Y' is a methyl ketone.
• Only aldehydes and alcohols can oxidise to form such a compound.
• Among the options, only CH₃CHO (acetaldehyde) can be oxidised to yield a methyl ketone.

Thus, the most suitable candidate for compound 'X' is CH₃CHO.

NaHSO₃ (sodium bisulfite) reacts with certain organic compounds, specifically those containing reactive carbonyl groups.

• Aldehydes and ketones typically react with NaHSO₃ to form addition products.
• For instance, benzaldehyde and acetaldehyde will readily react due to their carbonyl groups.
• However, acetone, a simple ketone, does not exhibit this reactivity under standard conditions.
• Thus, among the listed compounds, acetone is the one that does not react with NaHSO₃.

The reaction of an alkyl halide with alcoholic KOH is known as.

• Dehydrohalogenation is the process in which an alkyl halide reacts with alcoholic KOH.
• This reaction leads to the formation of an alkene by eliminating a halide ion and a hydrogen atom.
• It is a common method for synthesising alkenes from alkyl halides.

The reagent that reacts with glucose to form a crystalline osazone derivative is:

• Phenylhydrazine is the specific reagent used to produce osazones from sugars.
• When glucose reacts with phenylhydrazine, it leads to the formation of distinct crystalline structures.
• This reaction is important for identifying and characterising reducing sugars.

The molecule with the highest dipole moment is determined by its molecular structure and the electronegativity of its atoms.

• CH₃Cl: This molecule has a moderate dipole moment due to the presence of one chlorine atom, which is more electronegative than carbon and hydrogen.
• CH₂Cl₂: With two chlorine atoms, this molecule has a higher dipole moment than CH₃Cl, as the dipole moments of the two Cl atoms do not cancel each other out completely.
• CHCl₃: Featuring three chlorine atoms, CHCl₃ has an even greater dipole moment, as the individual dipoles reinforce each other, resulting in a stronger overall dipole.
• CCl₄: This molecule has a symmetrical tetrahedral shape, which causes the dipole moments to cancel out, resulting in a zero dipole moment.

Consequently, CHCl₃ exhibits the highest dipole moment among the listed options.

The compound or ion used in the nitration of benzene is the nitronium ion.

In the nitration process, the following key points are important:

• The reaction typically involves a combination of nitric acid and sulphuric acid.
• This mixture generates the nitronium ion (NO₂⁺), which is the active species that initiates the reaction with benzene.
• The nitronium ion acts as an electrophile, attacking the electron-rich benzene ring.

Thus, while nitric and sulphuric acids are essential for generating the nitronium ion, it is the nitronium ion that directly participates in the nitration of benzene.

When HNO₃ contacts skin and is then washed away, it can turn yellow. This indicates the presence of:

• NO₂ (nitrogen dioxide) is often responsible for the yellow colour.
• Other nitrogen compounds, such as N₂O (nitrous oxide), NO (nitric oxide), and N₂O₃ (dinitrogen trioxide), do not typically cause this reaction.
• The yellow colouration is a result of the formation of nitrogen dioxide, which can occur in certain conditions.

The total number of possible values of the magnetic quantum number for l = 3 is determined by the formula:

• The magnetic quantum number, m_l, can take values from -l to +l.
• For l = 3, the possible values are:
• -3
• -2
• -1
• 0
• +1
• +2
• +3
• This results in a total of 7 values.

Thus, the total number of possible values of the magnetic quantum number for l = 3 is 7.

To determine the number of moles of helium gas in 22.4 L at 0°C and 1 atm pressure:

• Use the Ideal Gas Law, which states that 1 mole of an ideal gas occupies 22.4 L at standard conditions (0°C and 1 atm).
• Since the volume of helium given is 22.4 L, this corresponds exactly to 1 mole.
• Therefore, the amount of helium gas in this scenario is 1.0 moles.

Carboxylic acids are generally more acidic than phenols and alcohols due to several factors:

• Resonance stabilization: The conjugate base of carboxylic acids benefits from resonance, allowing the negative charge to be delocalised over multiple atoms. This stabilisation makes carboxylic acids more likely to donate a proton.
• Highly acidic hydrogen: The hydrogen atom in carboxylic acids is more acidic compared to those in phenols and alcohols, contributing to their stronger acidic nature.
• Intermolecular interactions: While hydrogen bonding can play a role in the behaviour of alcohols and phenols, it does not significantly enhance their acidity compared to carboxylic acids.

To determine the number of sigma bonds in P₄O₁₀:

• Each phosphorus atom is bonded to three oxygen atoms and shares connections with other phosphorus atoms.
• In P₄O₁₀, there are four phosphorus atoms.
• The bonding structure includes:
• 3 sigma bonds from each phosphorus to oxygen.
• 1 sigma bond between each pair of phosphorus atoms.
• Calculating total sigma bonds:
• From phosphorus to oxygen: 4 phosphorus × 3 bonds = 12 bonds.
• Between phosphorus atoms: 3 bonds (as there are 4 phosphorus atoms forming a tetrahedral structure).
• Adding these gives:
• 12 (P-O) + 3 (P-P) = 15 sigma bonds.

Thus, the total number of sigma bonds in P₄O₁₀ is 15.

The rate constant of a reaction is influenced by several factors:

• Temperature: This is the most significant factor affecting the rate constant. Higher temperatures generally increase the rate of reaction.
• Reaction conditions: These include pressure and concentration, which can also impact the rate constant.
• Catalysts: The presence of a catalyst can lower the activation energy, thereby increasing the rate constant.

Other factors such as mass and weight are less relevant in this context, while time is not a direct factor influencing the rate constant itself.

A catalyst X is a substance that speeds up a chemical reaction without being consumed in the process. Here are some key points about its effects:

• Enthalpy: It does not reduce the overall enthalpy of the reaction.
• Rate constant: It does not decrease the rate constant; instead, it increases the reaction rate.
• Activation energy: It lowers the activation energy required for the reaction to proceed.
• Equilibrium constant: The catalyst does not change the equilibrium constant of the reaction.

ΔU = - 6.12 x 1.23 x GMM (NH₄NO₃)
= - 6.12 x 1.23 x 80 = - 602.208 kJ mol^-1

ΔH = -55.2 KJ.mol^-1
-[H⁺ _(aq) + OH^- _(aq) → H₂O_(l) ΔH = -57.3 KJ .mol^-1]]

CH₂COOH_aq → CH₃COO^- _(aq) + H⁺ _(aq) ΔH = ?
CH₂COOH_(aq) + OH^- _(aq) → CH₃COO^- _(aq) + H₂O_(l) ΔH = -55.2 KJ .mol^-1
-H⁺ + OH^- _(aq) → - H₂O_(l) ΔH = + 57.3KJ .mol^-1
CH₃COOH_(aq) → CH₃COO^- _(aq) + H⁺_(aq) ΔH = 2.1 KJmol^-1

Iodex is a commonly used medication in healthcare.

It primarily contains the following active ingredients:

• Methyl salicylate - Known for its pain-relieving properties.
• Ethyl salicylate - Often used for its anti-inflammatory effects.
• Acetylsalicylic acid - Widely recognised as aspirin, it reduces pain and fever.
• o-Hydroxybenzoic acid - Also known as salicylic acid, it has various medicinal uses.

Each ingredient plays a significant role in providing relief from pain and inflammation.

IUPAC Name Analysis

• The IUPAC name is essential for identifying chemical compounds accurately.
• Review the structure carefully to determine the correct naming convention.
• Key components to identify include:
• Functional groups, such as cyano groups.
• Substituents, like methyl groups.
• The longest carbon chain to establish the base name.
• After analysing the structure, assign the appropriate name based on IUPAC rules.

As the alkali metals have minimum ionisation potential in the periodic table, secondly ionisation potential decreases on moving top to bottom in periodic table, thus Mg has highest ionisation enthalpy among the given elements, hence it requires radiation of highest frequency to cause emission of electrons.

Conductivity is a measure of how well a solution can conduct electricity. It depends on various factors, and understanding these relationships is key to determining the unit of the constant of proportionality. Here’s a breakdown of the relationships involved:

• Directly proportional factors:
  • Area of the vessel
  • Concentration of the solution
• Inversely proportional factor:
  • Length of the vessel

To find the unit of the constant of proportionality, we combine these relationships:

• Conductivity (S) = k × (Area (m²) × Concentration (mol/m³)) / Length (m)

Rearranging gives:

• k = Conductivity × Length / (Area × Concentration)

Considering the units:

• Unit of Conductivity: S
• Unit of Length: m
• Unit of Area: m²
• Unit of Concentration: mol/m³

Substituting these units into the equation provides:

• k = S × m / (m² × (mol/m³))
• k = S × m³ / (m² × mol)
• k = S m² mol^-1

Thus, the unit of the constant of proportionality is S m² mol^-1.

A real gas behaves more like an ideal gas under specific conditions. Here are the key factors influencing this behaviour:

• Low Pressure: At low pressures, gas particles are further apart, reducing interactions between them.
• High Temperature: Increased temperature gives gas particles more energy, allowing them to overcome intermolecular forces.
• Real gases tend to behave ideally when:

• The pressure is low (close to atmospheric pressure).
• The temperature is high (well above the gas's critical temperature).

Thus, options with low pressure and high temperature are preferable for ideal gas behaviour.

The reaction of benzene with n-propyl chloride in the presence of anhydrous AlCl₃ leads to the formation of predominantly:

• n-Propyl benzene is the main product of this reaction.
• The reaction involves an electrophilic aromatic substitution mechanism.
• Aluminium chloride (AlCl₃) acts as a catalyst, facilitating the formation of the electrophile.
• Due to the structure of n-propyl chloride, the reaction primarily yields the linear alkyl substituent.

To determine the hydrogen ion concentration in a solution of acetic acid:

• We start with a concentration of 0.2 M for CH₃COOH.
• Given that it is 40% dissociated, we can calculate the amount of acetic acid that has dissociated.
• Calculate the dissociated concentration: 0.2 M x 0.40 = 0.08 M.
• This value represents the concentration of hydrogen ions (H⁺) produced from the dissociation.

The hydrogen ion concentration is therefore 0.08 M.

In which of the following separation methods is only one enantiomer recovered from the racemic mixture?

• Chemical methods can selectively react with one enantiomer.
• Electrical methods may separate enantiomers based on charge differences.
• Biological processes often favour one enantiomer due to enzyme specificity.
• Mechanical separation typically does not differentiate between enantiomers.

Among these methods, chemical and biological techniques often successfully isolate a single enantiomer from a racemic mixture.

Bismuth is the final product of a radioactive disintegration series known as:

• The disintegration series can be classified into different categories based on the number of nucleons, specifically:
  • 4n - These series do not end with Bismuth.
  • 4n + 1 - These series also do not conclude with Bismuth.
  • 4n + 2 - This series is not associated with Bismuth.
  • 4n + 3 - This is the series in which Bismuth is the end product.

To identify the strongest base among the given options, consider the following factors:

• Base Strength: A strong base completely dissociates in solution, producing hydroxide ions (OH^-) and increasing the pH significantly.
• Structure: The presence of alkali or alkaline earth metals typically indicates stronger bases.
• Solubility: Highly soluble compounds in water tend to exhibit stronger basicity.

Reviewing the options provided, look for the compound that meets these criteria most effectively to determine the strongest base.

The reduction of benzoyl chloride with H₂/Pd-BaSO₄ produces:

• Benzyl alcohol: This is the primary alcohol formed from the reduction process.
• Benzaldehyde: This compound is not the main product; it is a potential intermediate but does not form directly from this reduction.
• Benzoic acid: This is not produced in the reduction of benzoyl chloride.
• Benzoyl cyanide: This compound is unrelated to the reduction process.

Which of the following is an example of natural polymer?

• Wool is a natural polymer made from protein fibres produced by sheep.
• Orlon, Teflon, and polystyrene are synthetic polymers.
• Natural polymers are derived from biological sources, while synthetic ones are manufactured through chemical processes.

The molecular mass of a volatile substance can be determined using various methods. One effective technique is:

• Victor-Meyer's method: This method is specifically designed for measuring the molecular mass of volatile substances through vapour displacement.

The strongest reducing agent among the halide ions is I^-.

• I^- is the most effective reducing agent due to its ability to donate electrons readily.
• As you move up the group from iodine to fluorine, the reducing strength decreases.
• Consequently, F^- is the weakest reducing agent, as it is more stable and less likely to donate electrons.

Anti-ferromagnetism is a property of materials where adjacent magnetic moments align in opposite directions.

In this context, we can identify the anti-ferromagnetic arrangement as follows:

• The pattern ↑↓↑↓ represents adjacent spins that are oppositely aligned, characteristic of anti-ferromagnetism.
• Other patterns, such as ↑↑↑↓↓, ↑↑↑↑↑, and ↓↓↓↓↓, show parallel or uniform alignment, which do not exhibit anti-ferromagnetic behaviour.

Thus, the correct representation of anti-ferromagnetism is ↑↓↑↓.