VITEEE Chemistry Test - 4 - JEE MCQ

The conversion of propene to 1-Propanol can be effectively achieved through oxidation. Here are the ideal reagents to use:

• Alkaline KMnO₄ - This reagent is well-known for its ability to oxidise alkenes to alcohols.
• B₂H₆ and alkaline H₂O₂ - This combination provides a hydroboration-oxidation pathway, leading to the desired alcohol.
• O₃/Zn dust - Ozonolysis followed by reduction can also yield the alcohol from the alkene.
• OsO₄/CH₄, Cl₂ - While useful for dihydroxylation, it is not the most straightforward for generating 1-Propanol specifically.

Among these, B₂H₆ and alkaline H₂O₂ is the most effective choice for producing 1-Propanol from propene.

Schiff's reagent is a chemical solution commonly used in laboratories for certain types of staining in microscopy. It is particularly known for its role in identifying aldehydes in organic compounds. Here are some key points about Schiff's reagent:

• It is made from rosaniline hydrochloride.
• When exposed to an aldehyde, it forms a pink or magenta colour.
• This reaction is used in histology to stain tissues and identify specific cellular components.
• It is a vital tool in both academic and medical research settings.

When propene reacts with HBr in the presence of peroxide, the reaction follows a different pathway than usual.

This process is known as the anti-Markovnikov addition. Here’s how it works:

• The peroxide initiates the reaction, leading to the formation of a free radical.
• This free radical prefers to add to the less substituted carbon of propene.
• As a result, bromine attaches to the terminal carbon atom, producing 1-bromopropane.

Thus, the major product of this reaction is 1-bromopropane.

Benzaldehyde reacts with ammonia to form:

• Benzaldehyde ammonia - A direct reaction product.
• Urotropine - A potential outcome through further reactions.
• Hydrobenzamide - Resulting from amine substitution.
• Ammonium chloride - Not a direct product of this reaction.

The reactivity of carbonyl compounds in nucleophilic addition reactions can be ranked by their structure and substituents.

• H₂C=O (formaldehyde) is the most reactive.
• Next, RCHO (aldehydes) follow in reactivity.
• ArCHO (aromatic aldehydes) are less reactive than aliphatic aldehydes.
• R₂C=O (ketones) are less reactive than aldehydes.
• Finally, Ar₂C=O (aromatic ketones) are the least reactive.

This order is primarily influenced by the electron-donating or withdrawing effects of the substituents attached to the carbonyl carbon.

The reaction or method that does not produce an alkane is:

• Catalytic hydrogenation of alkenes: This method converts alkenes into alkanes by adding hydrogen. It results in the formation of alkanes.
• Wurtz reaction: This reaction involves the coupling of alkyl halides in the presence of sodium, leading to the formation of alkanes.
• Kolbe's electrolytic method: This process generates alkanes from carboxylic acids through electrolysis, resulting in alkane production.
• Dehydrohalogenation of an alkyl halide: This method typically results in alkenes rather than alkanes, as it involves the elimination of hydrogen halide from the alkyl halide.

The number of significant figures in 40.00 is four.

To determine the number of significant figures, consider the following points:

• The digits in 40.00 include 4 and 0.
• All non-zero digits are always significant.
• Any zeros between significant digits are also significant.
• Trailing zeros in a decimal number are significant.

Thus, 40.00 has a total of four significant figures: 4, 0, 0, and 0.

To determine the lowest molecular mass of compound X:

• Start with the products of combustion: 2.63 g of CO₂ and 1.28 g of H₂O.
• Calculate moles of CO₂:
  • Using the formula: moles = mass / molar mass.
  • Molar mass of CO₂ = 44 g/mol.
  • Moles of CO₂ = 2.63 g / 44 g/mol = 0.0598 moles.
• Calculate moles of H₂O:
  • Molar mass of H₂O = 18 g/mol.
  • Moles of H₂O = 1.28 g / 18 g/mol = 0.0711 moles.
• Determine the moles of carbon and hydrogen:
  • Each mole of CO₂ contains 1 mole of carbon.
  • Each mole of H₂O contains 2 moles of hydrogen.
  • Thus, carbon = 0.0598 moles and hydrogen = 2 × 0.0711 moles = 0.1422 moles.
• Calculate the mass of carbon and hydrogen:
  • Mass of carbon = 0.0598 moles × 12 g/mol = 0.7176 g.
  • Mass of hydrogen = 0.1422 moles × 1 g/mol = 0.1422 g.
• Find the total mass accounted for:
  • Total mass = mass of carbon + mass of hydrogen = 0.7176 g + 0.1422 g = 0.8598 g.
• Determine the mass of the other elements in compound X:
  • Mass of X = 0.858 g (initial mass) - 0.8598 g (mass from combustion) = -0.0018 g.
  • This suggests that there are likely other elements present in the compound that were not considered.
• Estimate the molecular mass:
  • Molecular mass can be calculated from the ratio of carbon and hydrogen moles.
  • By balancing the equation and considering potential additional elements, the lowest molecular mass of X is approximated.

Fatty acids are the building blocks of fats, while glucose serves as a fundamental unit for various carbohydrates. Here are the key carbohydrates that glucose can form:

• Cellulose: A structural component in plant cell walls.
• Glycogen: The storage form of glucose in animals, primarily found in liver and muscle tissues.
• Starch: A storage form of glucose in plants, commonly found in tubers and grains.

Thus, glucose can be related to several forms of carbohydrates, including cellulose, glycogen, and starch.

Amino acids serve as the essential components of proteins. They play a crucial role in various bodily functions and are vital for:

• Building tissues - Amino acids help in the growth and repair of muscles and organs.
• Enzyme production - They are necessary for creating enzymes that facilitate biochemical reactions.
• Hormone synthesis - Amino acids contribute to the formation of hormones that regulate bodily functions.

In summary, amino acids are fundamental for the structure and function of proteins in the body.

The reaction of various compounds with KMnO₄ followed by acidification can lead to the formation of benzoic acid. However, some compounds do not undergo this transformation. Here’s a breakdown of each option:

• Benzyl alcohol: This compound is oxidised to benzoic acid.
• Acetophenone: This compound also yields benzoic acid upon oxidation.
• Anisole: This compound does not produce benzoic acid due to the presence of the methoxy group, which hinders oxidation.
• Toluene: Like benzyl alcohol, it is oxidised to benzoic acid.

Thus, the compound that will not yield benzoic acid upon reaction with KMnO₄ followed by acidification is anisole.

The hydrolytic reaction of fats using caustic soda is called saponification.

• Saponification is the process where fats are broken down into glycerol and fatty acids.
• This reaction typically involves a strong base, such as caustic soda (sodium hydroxide).
• During saponification, the ester bonds in triglycerides are hydrolysed.
• The result is the formation of soap, which consists of the salts of fatty acids.

A defining feature of reversible reactions is that they:

• Do not proceed to completion, meaning they can reach a state of equilibrium.
• At equilibrium, both reactants and products are present in varying concentrations.
• Changes in concentrations of reactants or products can shift the equilibrium position.

The equilibrium constant for a reversible chemical reaction at a specific temperature:

• Does not depend on the initial concentrations of reactants.
• Is determined by the concentrations of products and reactants once the system reaches equilibrium.
• Is a characteristic value for the reaction at that temperature.

In an electrochemical cell, the relationship between Gibbs free energy change (∆G^o) and electromotive force (E^o) is given by:

• ∆G^o represents the change in free energy at standard conditions.
• E^o is the standard cell potential.
• For a reaction involving n moles of electrons, the equation is:

∆G^o = -nFE^o

• Where F is Faraday's constant, approximately 96485 C/mol.
• This indicates that a positive cell potential results in a negative Gibbs free energy change, signifying that the reaction is spontaneous.

The enthalpy of a solution of KNO₃ is + 35.64 kJ. This denotes:

The positive enthalpy value indicates that the process involves the absorption of heat. Key points include:

• The solution absorbs heat from the surroundings.
• This results in a cooling effect in the environment.
• Such processes are referred to as endothermic reactions.

An antipyretic is a medication used to reduce fever.

• Common examples include paracetamol, which is widely used for its effectiveness and safety profile.
• Other substances like quinine are not primarily used for fever reduction.
• Medications such as luminal and piperazine do not have antipyretic properties.

Tautomerism is a phenomenon where isomers differ in the position of protons and electrons. It typically occurs in compounds containing a hydrogen atom attached to a heteroatom, such as nitrogen or oxygen. Here’s a brief overview of the compounds listed:

• (CH₃)₃CNO: This compound can exhibit tautomerism due to the presence of the nitrogen atom.
• (CH₃)₂NH: This amine does not typically show tautomerism as it lacks the necessary structural features.
• R₃CNO₂: The presence of both nitrogen and oxygen means this compound can also display tautomerism.
• RCH₂NO₂: Like the previous examples, this compound can exhibit tautomerism due to its structure.

In summary, compounds capable of tautomerism typically involve a functional group with hydrogen atoms that can shift positions, particularly those containing nitrogen or oxygen. Therefore, (CH₃)₃CNO, R₃CNO₂, and RCH₂NO₂ are likely candidates for exhibiting this phenomenon.

Geometry, Hybridization, and Magnetic Moments of Ions

• [Ni(CN)₄]²⁻:
  • Geometry: Tetrahedral
  • Hybridization: sp³
  • Magnetic Moment: 5.9
• [MnBr₄]²⁻:
  • Geometry: Square planar
  • Hybridization: dsp²
  • Magnetic Moment: 0
• [FeF₆]³⁻:
  • Geometry: Octahedral
  • Hybridization: sp³d²
  • Magnetic Moment: 4.9

The complex with a square planar structure is [NiCl₄]²⁻.

• Ni(CO)₄ has a tetrahedral geometry.
• [Ni(H₂O)₆]²⁺ exhibits an octahedral structure.
• [Cu(NH₃)₄]²⁺ typically forms a tetrahedral arrangement.

Thus, among the given options, only [NiCl₄]²⁻ is known for its square planar configuration.

The reagent that can effectively convert benzene diazonium chloride into benzene is:

• H₃PO₂ (phosphorous acid) is a reducing agent that facilitates this conversion.
• Other reagents, such as CH₃OH, Br₂-H₂O, and LiAlH₄, are not suitable for this transformation.

To determine the electrode potential of the Cu²⁺/Cu electrode at a concentration of 0.01 M and 298 K, we use the Nernst equation.

Nernst Equation:

E = E° - (0.0591 / n) × log₁₀(1 / [Cu²⁺])
(This form is used at 298 K)

Given Data:

• Standard electrode potential (E°) = 0.34 V

• Concentration of Cu²⁺ = 0.01 M

• Temperature = 298 K

• Number of electrons, n = 2

Step-by-Step Calculation:

E = 0.34 - (0.0591 / 2) × log₁₀(1 / 0.01)
E = 0.34 - (0.0591 / 2) × log₁₀(100)
E = 0.34 - (0.0591 / 2) × 2
E = 0.34 - 0.0591
E = 0.2809 V

Rounded off:

E ≈ 0.281 V

Final Answer:

(b) 0.281 V

To find the potential of the aluminium electrode:

• The total EMF of the galvanic cell is given as 2.0 V.
• The potential of the copper electrode is +0.34 V.
• The relationship between the EMF, copper potential, and aluminium potential can be expressed as:
• EMF = E(copper) - E(aluminium)
• Substituting the known values:

2.0 V = 0.34 V - E(aluminium)

• Rearranging the equation gives:
• E(aluminium) = 0.34 V - 2.0 V
• This simplifies to:
• E(aluminium) = -1.66 V

The potential of the aluminium electrode is therefore -1.66 V.

In the electrorefining process of copper, a small amount of gold is found in:

• Anode mud - This is the residue that accumulates at the anode during the electrorefining process. It contains precious metals such as gold.
• Cathode mud - This is typically cleaner and primarily consists of pure copper deposits.
• Electrolyte - This solution facilitates the transfer of ions but does not generally accumulate solid impurities.
• Cathode - This is where pure copper is deposited, with minimal accumulation of other metals.

The correct answer is that gold primarily accumulates in the anode mud.

The ether that can undergo an electrophilic substitution reaction is:

• Electrophilic substitution reactions typically involve aromatic compounds.
• The presence of an electron-donating group enhances the reactivity of the aromatic ring.
• Among the given options, ethers with aromatic structures are more likely to participate in such reactions.
• For example, the ether with a phenyl group, namely C₆H₅OCH₃, is capable of undergoing electrophilic substitution.

Several blocks of magnesium are fixed to the bottom of a ship to:

• Prevent damage from underwater rocks.
• Discourage sharks from approaching.
• Reduce the overall weight of the vessel.
• Protect against the effects of water and salt.

The constant R is defined as:

• Work done per degree per mole.

This means that R represents the energy required to change the temperature of one mole of a substance by one degree. It is a fundamental constant in thermodynamics and plays a crucial role in equations relating to gases and their behaviour.

The compound BiCl₅ does not exist.

This conclusion is based on the following points:

• Bismuth typically forms compounds in lower oxidation states, such as +3.
• Compounds like BiCl₃ are stable, whereas BiCl₅ is not feasible.
• In contrast, other compounds mentioned, like AsCl₅ and SbCl₅, are known to exist.

Therefore, BiCl₅ is the only compound that does not exist among the options provided.

Silicon can be produced through various methods, including:

• Reaction of SiO₂ with magnesium: This method involves reducing silicon dioxide using magnesium, which can yield silicon.
• Heating carbon in an electric furnace: This process allows for the purification of silicon by using high temperatures to convert silicon compounds into silicon.
• Heating potassium flurosilicate: By reacting potassium flurosilicate with potassium, silicon can also be obtained.

Each method has its own advantages and applications in laboratory settings.

The acid that produces two series of salts is known for its ability to form various compounds.

• H₃PO₄ - Phosphoric acid, which forms phosphate salts.
• H₃PO₃ - Phosphorous acid, yielding phosphite salts.
• H₃BO₃ - Boric acid, typically forms borate salts.
• H₃PO₂ - Hypophosphorous acid, generates hypophosphite salts.

Among these acids, the one that distinctly forms two series of salts is H₃PO₄, producing both mono- and di-basic salts.