VITEEE Chemistry Test - 9 - JEE MCQ

Ethyl alcohol, when it reacts with certain substances, can produce compounds that have a fruity aroma. Among the options provided, the most relevant reactions are:

• With Acetic Acid (CH₃COOH): This reaction forms ethyl acetate, which is known for its fruity smell.
• With Acetone (CH₃COCH₃): This can also lead to the formation of fruity-scented compounds.

Other options, such as PCl₅ and K₂Cr₂O₇ with H₂SO₄, do not typically yield fruity-smelling compounds when reacting with ethyl alcohol.

Acetaldehyde and acetone exhibit different behaviours in their reactions with various reagents. Here are the key differences:

• Sodium bisulphide: Acetaldehyde reacts to form a thiol, while acetone does not react.
• Ammonia: Acetaldehyde can form an imine, whereas acetone is less reactive in this regard.
• Phosphorus pentachloride: Acetaldehyde reacts to form an acyl chloride, while acetone shows different reactivity.
• Phenylhydrazine: Acetaldehyde forms a hydrazone, whereas acetone reacts differently.

This variability in reactivity is due to the structural differences between acetaldehyde and acetone.

Compound A has the molecular formula C₂Cl₃OH. It reduces Fehling's solution and upon oxidation, it yields a monocarboxylic acid B. Additionally, A can be synthesised by reacting chlorine with ethanol.

• Compound A: C₂Cl₃OH
• Reduces: Fehling's solution
• Oxidation product: Monocarboxylic acid B
• Synthesis: From the action of Cl₂ on ethanol

Given these details, compound A is identified as Chloral, which fits the description perfectly.

Carbonyl compounds undergo nucleophilic addition due to several factors:

• Electronegativity difference: The varying electronegativity between carbon and oxygen creates a polar bond, making the carbon atom a target for nucleophiles.
• Electromeric effect: This effect facilitates the movement of electrons towards the more electronegative oxygen, enhancing nucleophilic attack.
• Stability of intermediates: The resulting anion on oxygen is generally more stable than a carbonium ion, favouring the nucleophilic addition process.

The acid-catalysed hydration of alkenes, excluding ethene, typically results in:

• Formation of a mixture of secondary and tertiary alcohols.
• The reaction involves the addition of water across the double bond of an alkene.
• The stability of the carbocation intermediate influences the outcome.
• More stable carbocations, such as tertiary, lead to predominance of tertiary alcohols.
• This process does not favour the formation of primary alcohols.

Light year is not a unit of time; rather, it measures distance based on how far light travels in a year. The other options are indeed units of time:

• Lunar month: The time taken for the Moon to complete a full cycle of phases.
• Leap year: A year that includes an extra day, making it 366 days long, to keep the calendar year aligned with the Earth's orbit.
• Micro-second: A millionth of a second, used to measure very short time intervals.

Thus, the correct answer is that a light year does not refer to a unit of time.

A zwitterion is a molecule that contains both positive and negative charges.

• The compound must have both an amino group (–NH₂) and a carboxylic acid group (–COOH).
• In the provided options, the presence of these functional groups determines if a zwitterion can form.
• Option A has a carboxylic acid and an imine, which does not yield a zwitterion.
• Option B features an amino group and a carboxylic acid, allowing it to exist as a zwitterion.
• Option C contains a carboxylic acid, but the amine is part of an amide structure, not suitable for zwitterion formation.
• Option D has two carboxylic acid groups, which do not provide the necessary amino group.

Thus, the only compound that can exist in a zwitterion structure is from option B, due to its combination of the required functional groups.

The organic compound with the formula C₆H₁₂O₆ exhibits specific characteristics:

• It reacts with phenylhydrazine to form a yellow crystalline solid.
• When reduced with sodium, it produces a mixture of sorbitol and mannitol.

This behaviour is indicative of a monosaccharide. Among the options provided:

• Fructose: A ketohexose that does not typically yield sorbitol and mannitol upon reduction.
• Glucose: An aldose that fits the criteria, producing both sorbitol and mannitol.
• Mannose: Another aldose but primarily yields mannose upon reduction.
• Sucrose: A disaccharide that does not match the formula.

Based on these characteristics, the most likely candidate is glucose.

The tripeptide hormone found in most living cells is

• Glutathione - a vital antioxidant.
• Composed of three amino acids: cysteine, glutamine, and glycine.
• Plays a key role in cellular processes and detoxification.
• Essential for maintaining cellular health and function.

Saponification of ethyl benzoate with caustic soda results in:

• Sodium benzoate
• Ethanol

The process involves:

• Hydrolysis of ethyl benzoate in the presence of caustic soda.
• Formation of the salt, sodium benzoate, and ethanol as by-products.

The reaction of carbon monoxide with caustic soda (NaOH) can yield a specific salt.

The main product of this reaction is sodium formate, which is represented by the formula HCOONa. Here are the key points to understand:

• Carbon monoxide reacts with NaOH in a process known as carbonylation.
• This reaction forms sodium formate, an important compound in various industrial applications.
• Sodium formate can be used in textile and leather industries as well as in the production of formic acid.

To identify compounds that do not contain a carboxyl group, consider the following:

• Picric acid: Contains a nitro group but no carboxyl group.
• Aspirin: Contains an acetylsalicylic acid structure with a carboxyl group.
• Benzoic acid: This compound is defined by its carboxyl group.
• Ethanoic acid: Commonly known as acetic acid, it has a carboxyl group.

Thus, the compound that does not have a carboxyl group is Picric acid.

According to Le-Chatelier's principle, adding heat to a solid and liquid in equilibrium will cause the

• The temperature will rise.

• This heat addition shifts the equilibrium towards the endothermic process.

• As a result, the amount of liquid will increase.

• Conversely, the amount of solid will decrease.

When helium gas is added to a vessel at equilibrium containing SO₃, SO₂, and O₂, while keeping the temperature and volume constant, the total pressure of the system increases.

According to Le Chatelier's principle:

• The system will respond to the increase in pressure.
• This response involves shifting the equilibrium to reduce the pressure.
• The reaction for the dissociation of SO₃ is:
• 2 SO₃ ⇌ 2 SO₂ + O₂
• Since the forward reaction produces more gas molecules, the equilibrium will shift:
• Towards the right to produce SO₂ and O₂.

As a result, the dissociation of SO₃ increases.

CH₄(g) + 2O₂ → CO₂(g) + 2H₂O(l)
Δn = 1 - 3 = (-2)
∴ ΔH - ΔE = Δn_g RT = (-2) (8.314) (300)

An endothermic reaction is characterised by the absorption of heat from its surroundings.

This type of reaction involves the following key points:

• Heat absorption: Energy is taken in, resulting in a temperature decrease in the surrounding environment.
• Examples: Common examples include photosynthesis and the dissolution of certain salts.
• Importance: Endothermic reactions play a crucial role in various natural processes and industrial applications.

To analyse the thermodynamic properties of the reaction:

• ΔH (Enthalpy Change): The combustion of hydrocarbons, such as C₈H₈, is an exothermic process. Thus, the enthalpy change (ΔH) is negative.
• ΔS (Entropy Change): The reaction produces a larger number of gas molecules (16 CO₂ + 18 H₂O) compared to the reactants (2 C₈H₈ + 25 O₂). This increase in disorder leads to a positive entropy change (ΔS).
• ΔG (Gibbs Free Energy Change): Since the reaction is exothermic and leads to an increase in entropy, the Gibbs free energy change (ΔG) is negative, indicating the reaction is spontaneous under standard conditions.

In summary, the signs for ΔH, ΔS, and ΔG are:

• ΔH: Negative
• ΔS: Positive
• ΔG: Negative

Azo dyes are synthetic dyes characterised by the presence of a nitrogen-nitrogen double bond (–N=N–). They are widely used in various applications, including textiles and food. Here are some key points about azo dyes:

• Structure: Azo dyes contain the azo group, which is responsible for their vibrant colours.
• Examples: Common azo dyes include Orange-I and many others used in different industries.
• Applications: They are employed in textiles, cosmetics, and food due to their bright colours.
• Environmental Concerns: Some azo dyes can release harmful substances upon degradation, raising environmental issues.

To identify the compound CH₃CH₂CH₂CH(CH=CH₂)CH₂CH₂CH₃:

• The compound has a long carbon chain with a total of seven carbon atoms.
• The double bond is located between the fourth and fifth carbon atoms, making it a hexene.
• There is a vinyl group (–CH=CH₂) attached to the fourth carbon.
• This structure can be named as 3-ethenylheptane, given the position of the double bond and the substituent group.

Thus, the correct name for the compound is 3-Ethenylheptane.

To determine which complex exhibits the highest paramagnetic behaviour, we need to consider the oxidation states and electron configurations of the metal centres involved.

• Vanadium (V)₂OH₂(NH₃)²]⁺:
  • Oxidation state: +4
  • Electron configuration: 3d²
  • Paramagnetic due to 2 unpaired electrons.
• Iron (Fe)₃)₂]²⁺:
  • Oxidation state: +2
  • Electron configuration: 3d⁶
  • Paramagnetic due to 4 unpaired electrons.
• Cobalt (Co)₂(OH)₂]²⁻:
  • Oxidation state: +2
  • Electron configuration: 3d⁷
  • Paramagnetic due to 3 unpaired electrons.
• Titanium (Ti)₃)₆]³⁺:
  • Oxidation state: +3
  • Electron configuration: 3d¹
  • Paramagnetic due to 1 unpaired electron.

Conclusion:

The complex with the highest paramagnetic behaviour is [Fe(en)(bpy)(NH₃)₂]²⁺, as it has the most unpaired electrons (4) compared to the others.

Sodium nitroprusside reacts with sulphide ions to create a purple colour, which is a key observation in this reaction.

• This colour change is due to the formation of a complex.
• The specific compound responsible for the purple colour is [Fe(CN)₅NOS]³⁻.
• This complex forms as a result of the interaction between sodium nitroprusside and sulphide ions.
• The presence of nitrogen oxide and sulphide contributes to the distinct colour observed.

Alkyl cyanides exhibit distinct polar characteristics when compared to alkyl isocyanides. Here are the key points regarding their polarity:

• Alkyl cyanides are generally less polar than their alkyl isocyanide counterparts.
• This difference in polarity can significantly impact their chemical behaviour and interactions.
• Understanding these properties is crucial in applications ranging from synthesis to environmental science.

The compound that gives a dye test is:

• Aniline is known to produce a dye test due to its aromatic amine structure.
• Methylamine does not typically yield a dye test.
• Diphenylamine is also not associated with a dye test.
• Ethylamine does not react in this manner either.

In summary, the only compound from the options that provides a positive reaction in a dye test is Aniline.

When the same quantity of electricity is passed through the solution of different electrolytes in series, the amounts of product obtained are proportional to their:

• The amounts of products formed during electrolysis depend on the chemical equivalents of the electrolytes.
• This relationship is a result of Faraday's laws of electrolysis, which state that the mass of a substance produced is directly proportional to the quantity of electricity passed.
• Thus, when comparing different electrolytes, the produced amounts will vary according to their respective chemical equivalents.

To determine if ions are present in the solutions:

• Sucrose in water: Sucrose does not dissociate into ions; it remains as neutral molecules.
• Sulphur in CS₂: Sulphur does not form ions in this solution; it stays as neutral atoms.
• Cesium nitrate in water: This compound dissolves and dissociates into cesium ions and nitrate ions, thus containing ions.
• Ethyl alcohol in water: Ethyl alcohol does not dissociate into ions; it remains as neutral molecules.

Conclusion: Only cesium nitrate in water contains ions.

The reagent used for preparing higher ethers from halogenated ethers is typically:

• Sodium alkoxide - This is the most common reagent for ether synthesis.
• Other reagents include dry silver oxide, which can also facilitate ether formation.
• Grignard reagents may be employed, but they react differently and are not the primary choice for this process.
• Concentrated sulphuric acid is not used for this purpose as it can lead to dehydration rather than ether formation.

In summary, sodium alkoxide is the primary reagent for synthesising higher ethers from halogenated ethers.

If the melting point of the metals is lower than that of impurities, the crude metals can be purified through the process of:

• Liquation - This technique exploits the difference in melting points to separate metals from their impurities.
• The metal melts and flows away from the impurities, which remain solid.
• This method is effective for metals with significantly lower melting points compared to their impurities.

The relationship that describes how vapour pressure changes with temperature is known as the:

• Clausius-Clapeyron equation

This equation is essential for understanding phase transitions, especially between liquid and vapour states. It provides a mathematical framework to predict how the vapour pressure of a substance varies with temperature, which is crucial in fields like meteorology and physical chemistry.

The question requires identifying the non-acidic compound from the given options.

• PCl₃, or phosphorus trichloride, is known for its acidic properties.
• SbCl₃, or antimony trichloride, also exhibits acidity.
• BiCl₃, or bismuth trichloride, is considered acidic as well.
• CCl₄, or carbon tetrachloride, is non-acidic and acts as a neutral compound.

Therefore, the compound that is not acidic is CCl₄.

The element with the highest first ionization potential is:

• Nitrogen has the highest first ionization potential among the options given.
• This is due to its stable electron configuration, which makes it more resistant to losing an electron.
• The first ionization potential increases across a period in the periodic table, and nitrogen is positioned in the middle of its group.
• In comparison, elements like boron, carbon, and oxygen have lower ionization potentials.