Chemical Reactions

The correct option is (B) :

3A→2B For the given reaction we can write rate of reaction: − = ​=− ​⇒+ = −

H₂O is dipolar, whereas BeF₂ is not. It is because: H₂O has polar covalent bonds, while BeF₂ has purely ionic bonds.

First, let's clarify the concept of a metal displacement reaction. In chemistry, a metal displacement reaction is a type of redox reaction. It involves a metal in a compound being displaced by another metal. This typically occurs because the displacing metal is more reactive than the metal being displaced. A typical example is when zinc displaces copper from copper sulfate solution:

Now, examining the given options, none of them are related to metal displacement reactions. In fact, all four options describe properties of noble gases:

1. Noble gases have large positive values of electron gain enthalpy: Noble gases indeed have positive electron gain enthalpy due to their stable electron configurations.
2. Noble gases are sparingly soluble in water: Noble gases do not easily dissolve in water, consistent with their inert nature.
3. Noble gases have very high melting and boiling points: Actually, this is incorrect. Noble gases have relatively low melting and boiling points due to weak dispersion forces.
4. Noble gases have weak dispersion forces: This is true; noble gases exhibit weak van der Waals forces, leading to low boiling and melting points.

Based on the above explanations, none of the options provided describe a metal displacement reaction. The correct option related to properties of noble gases was incorrectly identified. The correct factual statement about noble gases is:

• Noble gases have weak dispersion forces

This reinforces the understanding that noble gases typically have low melting and boiling points. Conclusively, if we are strictly discussing the options' correctness, it would be option mentioning weak dispersion forces relative to noble gases.

The question asks us to identify which of the given reactions is a metal displacement reaction. To solve this, we need to understand what a metal displacement reaction is.

A metal displacement reaction, also known as a single displacement or substitution reaction, involves one element being replaced by another in a compound. This typically occurs when a more reactive metal displaces a less reactive metal from its compound.

Let's analyze each option:

1. • This is a decomposition reaction where potassium chlorate decomposes into potassium chloride and oxygen gas. No displacement occurs here.
2. • In this reaction, aluminum displaces chromium from chromium(III) oxide to form aluminum oxide and free chromium. Here, aluminum, a more reactive metal, displaces chromium. This is a metal displacement reaction.
3. • This is also a displacement reaction, but it is specifically an example of a reaction between a metal and an acid to produce a salt and hydrogen gas, not strictly a metal-for-metal displacement.
4. • This is a decomposition reaction where lead(II) nitrate decomposes to form lead(II) oxide, nitrogen dioxide, and oxygen. Again, no displacement of a metal occurs.

From the analysis, option 2, , is the correct answer as it demonstrates a metal displacement reaction where aluminum, being more reactive, displaces chromium from its oxide compound.

Step 1: Understanding the Given Transformation

The transformation likely involves oxidation or hydroboration-oxidation, depending on the functional groups present.

Step 2: Analyze the Reagents

• followed by : This is the hydroboration-oxidation reaction, which converts an alkene to an anti-Markovnikov alcohol.
• PCC (Pyridinium Chlorochromate): A mild oxidizing agent that converts primary alcohols to aldehydes and secondary alcohols to ketones.
• Chromic acid ( ) in acidic medium: A strong oxidizing agent that converts alcohols to carboxylic acids.
• Acidic water ( ): Used for hydration of alkenes to form Markovnikov alcohols.

Step 3: Identify the Correct Set of Reagents

Since the transformation involves hydration followed by oxidation, the correct sequence of reagents is:

1. (Hydroboration step).
2. (Oxidation to form alcohol).
3. (Mild oxidation to aldehyde).

Step 4: Conclusion

The correct answer is:

Option (2): (i) , (ii) , (iii) PCC.

To determine which reagents glucose does not react with, let's analyze each option:

1. Tollen's Reagent: Glucose, being a reducing sugar, reacts with Tollen's reagent to give a positive result due to its aldehydic group.
2. Schiff's Reagent: This reagent is typically used to detect aldehydes after they are oxidized to carboxylic acids. Glucose does not undergo a reaction with Schiff's reagent directly in its normal state.
3. HCN (Hydrogen Cyanide): Glucose reacts with HCN to form cyanohydrin, indicating that there is an aldehydic carbonyl group available for reaction.
4. NH₂OH (Hydroxylamine): This reagent reacts with glucose to form oxime derivatives, as it reacts with the carbonyl (aldehyde) group of glucose.
5. NaHSO₃ (Sodium Bisulfite): Glucose does not form corresponding bisulfite addition products, so it does not react with NaHSO₃.

Given these explanations, the correct answer is that glucose does not react with Schiff's reagent (B) and Sodium Bisulfite (E).

The correct choice from the options provided is B and E.

Activation energy of any chemical reaction can be calculated if one knows the value of:

The Arrhenius equation relates the rate constant (k) of a chemical reaction to the temperature (T) and the activation energy (Ea):

$ = rate constant

If you have the rate constant at two different temperatures ( at and at ), you can use a modified form of the Arrhenius equation to calculate the activation energy:

\) :

\) $

Therefore, knowing the rate constant at two different temperatures is necessary to calculate the activation energy.

Let's break down this reaction sequence step by step to figure out the major product C.

Step 1: Reaction of 1-iodopropane with NaCN
The starting material is 1-iodopropane ( ). Sodium cyanide ( ) is a nucleophile. This reaction is a nucleophilic substitution reaction ( mechanism is favored for primary alkyl halides). The cyanide ion ( ) will displace the iodide ion ( ).

Therefore, product A is propanenitrile (also known as butyronitrile):

Step 2: Partial hydrolysis of propanenitrile (A) with
Nitriles can be hydrolyzed under basic or acidic conditions. Partial hydrolysis of a nitrile yields an amide.

So, product B is butanamide:

Step 3: Reaction of butanamide (B) with and
This reaction is the Hofmann bromamide degradation (also known as the Hofmann rearrangement). In this reaction, an amide reacts with bromine in an aqueous solution of sodium hydroxide to give a primary amine with one carbon atom less than the original amide. The carbonyl group is eliminated as carbonate.

So, butanamide ( ) will react with and to give propylamine:

Final Product:
Therefore, the major product C is propylamine.

The correct answer is (1) propylamine.

Final Answer:
The final answer is:

The rate of a reaction quadruples when temperature changes from 27°C to 57°C. Calculate the energy of activation.

Given R = 8.314 J K^-1 mol^-1, log 4 = 0.6021

Solution:

We can use the Arrhenius equation to solve this problem:

$ $

Therefore, the activation energy is approximately 38.04 kJ/mol.

Option 1: 38.04 KJ/mol

The given reactions involve the conversion of alcohols (ROH) to alkyl chlorides (RCl) using phosphorus chlorides (PCl₃ and PCl₅). Let's analyze each reaction to determine the products:

1. In the reaction 3ROH+PCl₃→3RCl+A, the alcohols react with phosphorus trichloride (PCl₃) to form alkyl chlorides (RCl) and a phosphorus-containing compound A as a byproduct. The balanced reaction is:

PCl₃ + 3ROH → 3RCl + H₃PO₃

Thus, the product A is H₃PO₃ (phosphorous acid).

2. In the second reaction ROH+PCl₅→RCl+HCl+B, the alcohol is converted to the alkyl chloride (RCl), and hydrogen chloride (HCl) is formed along with a phosphorus-containing compound B. Here, phosphorus pentachloride (PCl₅) breaks down, and the balanced equation is:

PCl₅ + ROH → RCl + HCl + POCl₃

Thus, the product B is POCl₃ (phosphoryl chloride).

Based on the analysis, the products A and B for each reaction are:

The correct answer is: H₃PO₃ and POCl₃.

Let's analyze each reaction in List-I and match it with the appropriate reagents/conditions in List-II.

(A) Conversion of cyclohexene to cyclohexanone:
This involves the oxidation of cyclohexene to form cyclohexanone. A common method for such conversions is ozonolysis followed by a reductive workup (using and ). Ozonolysis cleaves the double bond, and under reductive conditions, it can form aldehydes or ketones depending on the structure. For cyclohexene, this process yields cyclohexanone. Reagent (IV) corresponds to this description ( followed by ).
So, (A) matches with (IV).

(B) Conversion of benzene to benzophenone:
This involves the introduction of a benzoyl group ( ) to benzene, which is a Friedel-Crafts acylation reaction. The typical reagents for this reaction are an acyl halide (e.g., benzoyl chloride, ) and a Lewis acid catalyst (e.g., anhydrous ). Reagent (I) matches this description.
So, (B) matches with (I).

(C) Conversion of cyclohexanol to cyclohexanone:
This is a straightforward oxidation of a secondary alcohol to a ketone. Common oxidizing agents for this transformation include (chromium trioxide). Reagent (II) matches this description.
So, (C) matches with (II).

(D) Conversion of ethylbenzene to potassium benzoate:
This involves the oxidation of the alkyl side chain of benzene. When alkylbenzenes are treated with strong oxidizing agents like alkaline potassium permanganate ( ) under heating ( ), the alkyl group is oxidized to a carboxylate salt. Reagent (III) matches this description.
So, (D) matches with (III).

Final Matches:
(A) - (IV)
(B) - (I)
(C) - (II)
(D) - (III)

Final Answer:
The final answer is:

Step 1: Use the Reaction Quotient

The reaction quotient is given by:

$ with

The equilibrium constant is given as .

Since and , we see that:

\) $

Step 3: Direction of the Reaction

When , the reaction proceeds in the backward direction to achieve equilibrium.

Therefore, the reaction will shift to the left, and there is a tendency for the reaction to go in the backward direction.

Step 4: Conclusion

The correct answer is: Option (3): The reaction has a tendency to go in the backward direction.

Step 1: Analyze the Reaction

The reaction involves KMnO₄/H⁺, which is a typical oxidizing agent that cleaves alkenes and oxidizes the resulting fragments to carboxylic acids.

Step 2: Predict the Major Product

The oxidation of an alkene will cleave the double bond and convert both fragments into carboxylic acids. The correct product is:

$ $

Conclusion

The correct product is a pair of carboxylic acids formed by cleaving the alkene.