Explanation

To identify the correct option with the same empirical formula for both compounds, we need to understand what an empirical formula is. An empirical formula represents the simplest whole-number ratio of the atoms in a compound. Let's analyze each option to determine if the compounds share the same empirical formula.

(Option D) C6H12O6 & CH3COOH:

C6H12O6 (Glucose): The molecular formula is C6H12O6.

The ratio of carbon (C) to hydrogen (H) to oxygen (O) is 6:12:6, which simplifies to    1:2:1.

The empirical formula is CH2O.

CH3COOH (Acetic Acid): The molecular formula is CH3COOH.

The ratio of carbon (C) to hydrogen (H) to oxygen (O) is 2:4:2, which simplifies to 1:2:1.

The empirical formula is also CH2O.

Conclusion: The empirical formulas are the same (CH2O).

(Option A) H2O & H2O2:

H2O (Water): The molecular formula is H2O.

The ratio of hydrogen (H) to oxygen (O) is 2:1.

The empirical formula is H2O, as it's already in the simplest ratio.

H2O2 (Hydrogen Peroxide): The molecular formula is H2O2.

The ratio of hydrogen (H) to oxygen (O) is 2:2, which simplifies to 1:1.

The empirical formula is HO.

Conclusion: The empirical formulas are different (H2O vs. HO).

(Option B) C6H12 & C6H6:

C6H12 (Hexane): The molecular formula is C6H12.

The ratio of carbon (C) to hydrogen (H) is 6:12, which simplifies to 1:2.

The empirical formula is CH2.

C6H6 (Benzene): The molecular formula is C6H6.

The ratio of carbon (C) to hydrogen (H) is 6:6, which simplifies to 1:1.

The empirical formula is CH.

Conclusion: The empirical formulas are different (CH2 vs. CH).

(Option C) H2S2O3 & H2SO4:

H2S2O3 (Thiosulfuric Acid): The molecular formula is H2S2O3.

The ratio of hydrogen (H) to sulfur (S) to oxygen (O) is 2:2:3.

The empirical formula is H2S2O3, which cannot be simplified further.

H2SO4 (Sulfuric Acid): The molecular formula is H2SO4.

The ratio of hydrogen (H) to sulfur (S) to oxygen (O) is 2:1:4.

The empirical formula is H2SO4, which cannot be simplified further.

Conclusion: The empirical formulas are different (H2S2O3 vs. H2SO4).

Subject: Chemistry

Topic: Intro to Fundamental Concepts of Chemistry

Subtopic :Basic Concepts/ Empirical Formula

Difficulty Level: Hard

Flow chart for a substance containing elements A and X

Explanation

(Option B) Pressure: Pressure affects equilibrium in reactions involving gases when there is a difference in the number of moles of gaseous reactants and products. According to Le Chatelier's principle, increasing the pressure will shift the equilibrium towards the side with fewer gas molecules, and decreasing the pressure will shift it towards the side with more gas molecules. However, if the number of moles of gaseous reactants and products are equal, changes in pressure do not affect the position of equilibrium because there is no difference in the number of gas molecules on either side of the reaction.

(Option A) Temperature: Temperature is a critical factor in determining the position of equilibrium in a reversible reaction. According to Le Chatelier's principle, if the temperature is changed, the equilibrium will shift to counteract that change. For example, in an exothermic reaction (releases heat), increasing the temperature will shift the equilibrium to favor the reactants, whereas decreasing the temperature will favor the products. Thus, temperature does affect the equilibrium state.

(Option C) Volume: Volume is inversely related to pressure in a closed system (Boyle's Law). Thus, changes in volume affect the pressure. In reactions involving gases, changing the volume will affect the equilibrium if the number of moles of gaseous reactants and products are different. However, similar to pressure, if the number of moles of gaseous reactants and products are equal, changes in volume will not affect the equilibrium position.

(Option D) Catalyst: A catalyst speeds up the rate of both the forward and reverse reactions equally without being consumed in the reaction. It helps the system reach equilibrium faster, but it does not change the position of the equilibrium. Therefore, adding a catalyst does not affect the equilibrium concentrations of reactants and products.

Subject: Chemistry

Topic: Chemical Equilibrium

Subtopic: Le-Chatelier’s Principle

Difficulty Level: Moderate

Le Chatelier’s Principle

Definition: Le Chatelier’s Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change and restore a new equilibrium.

Explanation: Le Chatelier’s Principle helps predict how a change in conditions (such as concentration, temperature, or pressure) will affect the position of equilibrium in a reversible reaction.

Example:

Consider the reversible reaction:

N2(g)+3H2(g )⇌ 2NH3(g)+heat

• Increase in concentration of N2​: Shifts equilibrium to the right (towards NH3​).
• Increase in temperature: Shifts equilibrium to the left (towards N2​ and H2​) because the reaction is exothermic.
• Increase in pressure: Shifts equilibrium to the right (towards NH3​) because there are fewer gas molecules on the right side.
• Adding a catalyst: No change in the position of equilibrium; it only speeds up the attainment of equilibrium.

Le Chatelier’s Principle is a powerful tool for predicting how changes in conditions affect the equilibrium of chemical reactions.

Explanation

(Option B) Weak acid and salt of it with a strong base: This is the correct combination for an acidic buffer. An acidic buffer solution is made from a weak acid and its conjugate base, which is usually in the form of a salt. For example, acetic acid (a weak acid) and sodium acetate (the salt formed with a strong base, sodium hydroxide) form an acidic buffer. This mixture can maintain a relatively stable pH by neutralizing small amounts of added acid or base.

(Option A) Strong acid and salt of it with a weak base: This combination does not form a buffer solution. A buffer solution requires a weak acid or base to resist changes in pH when small amounts of strong acids or bases are added. A strong acid, which dissociates completely in water, cannot serve this function effectively.

(Option C) Strong acid and salt of it with a strong base: This combination will not create a buffer solution. A strong acid will dissociate completely, and the resulting solution will not have the necessary weak acid and its conjugate base to buffer the solution effectively.

(Option D) Weak acid and salt of it with a weak base: This combination also does not form a buffer solution. A weak acid and a weak base do not create a buffer because they do not provide the necessary weak acid and its conjugate base pair needed for buffering. Instead, the weak acid and weak base will not dissociate significantly, and thus, the solution will not resist changes in pH effectively.

Subject: Chemistry

Topic: Chemical Equilibrium

Subtopic: Acid base /Buffer solutions

Difficulty Level: Moderate

Key Facts

A buffer solution resists a change in pH when diluted or when small amounts of acid or alkali are added to it.

• Blood is one example of a natural buffer solution.
• The normal pH of human blood is 7.45.
• Alkalosis is a medical condition that causes high blood pH levels (over 7.45).
• Acidosis causes low blood pH levels (below 7.35).

Explanation

(Option D) Bond formed by the large-sized atoms is strong: This statement is incorrect. Bond strength is not solely determined by the size of the atoms involved. While larger atoms may have more electrons and thus more opportunities for bonding, the strength of a bond depends on various factors such as the type of bond (covalent, ionic, metallic), the electronegativity of the atoms, and the arrangement of electrons in the bonding orbitals. In many cases, smaller atoms tend to form stronger bonds because they have a greater attraction for electrons. Large atoms may form weaker bonds due to increased electron shielding and less effective nuclear charge.

(Option A) Bond is formed by the overlapping of half-filled orbitals: This statement is correct and refers to covalent bonding. Covalent bonds occur when atoms share electrons to achieve a stable electron configuration. When half-filled orbitals overlap, they share electrons, forming a covalent bond. This sharing of electrons helps each atom achieve a full outer electron shell, making the bond strong.

(Option B) Bond is formed by the attraction of positive and negative ions: This statement is also correct and describes ionic bonding. Ionic bonds form between atoms when one atom loses electrons (forming a positive ion) and another atom gains those electrons (forming a negative ion). The positive and negative ions then attract each other, forming a strong bond due to electrostatic forces.

(Option C) Bond is formed by the overlapping of “s” orbital is strong: This statement is correct. It refers to the formation of sigma bonds, which are strong covalent bonds formed by the overlapping of atomic orbitals. When "s" orbitals overlap, they form sigma bonds, which are strong and stable. Sigma bonds are typically formed in single bonds between atoms.

Subject: Chemistry

Topic: Chemical Bonding

Subtopic: Energetics of Bond

Difficulty Level: Moderate

Explanation

(Option C) Friedel-Crafts alkylation reaction: This reaction involves the introduction of an alkyl group onto an aromatic ring. In the presence of a Lewis acid catalyst like anhydrous aluminum chloride, the alkyl halide reacts with the aromatic compound, benzene in this case, leading to the substitution of one of the hydrogen atoms on the benzene ring with an alkyl group. This results in the formation of alkylbenzene.

(Option A) Halogenation: Halogenation is a reaction where a halogen atom is added to a compound. It usually occurs in the presence of a halogen such as chlorine or bromine. For example, in the case of benzene, halogenation could result in the substitution of one of its hydrogen atoms with a halogen atom.

(Option B) Friedel-Crafts acylation reaction: In this reaction, an acyl group (RCO-) is introduced onto an aromatic ring. It involves the reaction of an aromatic compound with an acyl halide or anhydride in the presence of a Lewis acid catalyst, typically aluminum chloride. This leads to the formation of ketones or aldehydes. So, this option involves the introduction of a carbonyl group onto the benzene ring, not an alkyl group.

(Option D) Sulphonation: Sulphonation is a reaction where a sulfonyl group (-SO3H) is introduced onto a molecule. It typically involves the substitution of a hydrogen atom with a sulfonyl group, often in the presence of a strong acid such as sulfuric acid. This reaction is often used to introduce sulfonic acid groups onto aromatic compounds.

Subject: Chemistry

Topic: Chemistry of Hydrocarbons

Subtopic: Alkyl halides

Difficulty Level: Moderate

Frieel-Crafts alkylation reaction

The Friedel-Crafts alkylation reaction

The Friedel-Crafts alkylation reaction involves the introduction of an alkyl group onto an aromatic ring. The general chemical reaction can be represented as follows:

Aromatic compound+Alkyl halide+Lewis acid catalyst  →

Alkylated aromatic compound+Hydrogen halide

For example

When benzene reacts with methyl chloride (CH3Cl) in the presence of a Lewis acid catalyst such as anhydrous aluminum chloride (AlCl3), the Friedel-Crafts alkylation reaction occurs, leading to the formation of toluene and hydrogen chloride:

Benzene+CH3Cl+AlCl3​→    Toluene+HCl

This reaction is important in organic synthesis for the preparation of alkylated aromatic compounds

.

Explanation

(Option D) Phenol: Phenol is an aromatic compound where a hydroxyl group (-OH) is directly bonded to a benzene ring. When sodium reacts with phenol, it forms sodium phenoxide and hydrogen gas. Phenol itself can be a precursor to benzene through reduction reactions. The reaction with sodium is:

2C₆​H₅​OH+2Na→2C₆​H₅​ONa+H₂​

However, phenol can be converted to benzene by reduction, typically using zinc dust:

C₆​H₅​OH+Zn→C₆​H₆​+ZnO

This reaction shows that phenol can indeed form benzene under specific conditions.

(Option A) Alcohol: "Alcohol" is a generic term that refers to any organic compound with one or more hydroxyl (-OH) groups attached to a carbon atom. The most common types are ethanol and methanol. Sodium (Na) reacts with alcohols to produce alkoxides and hydrogen gas but does not form benzene. For example:

2C₂​H₅​OH+2Na→2C₂​H₅​ONa+H₂​

This reaction produces sodium ethoxide and hydrogen gas, not benzene.

(Option B) Butyl Alcohol (Butanol): Butyl alcohol, also known as butanol, is a type of alcohol with four carbon atoms. Similar to other alcohols, when sodium reacts with butyl alcohol, it forms butoxide and hydrogen gas, not benzene. For example:

2C₄​H₉​OH+2Na→2C₄​H₉​ONa+H₂​

This produces sodium butoxide and hydrogen gas.

(Option C) Propanol: Propanol is a three-carbon alcohol. Sodium reacts with propanol in a manner similar to other alcohols, forming propoxide and hydrogen gas. The reaction is:

2C₃​H₇​OH+2Na→2C₃​H₇​ONa+H₂​

Here, sodium propoxide and hydrogen gas are formed, but not benzene.

Subject: Chemistry

Topic: Alcohols & Phenols

Subtopic: Phenol

Difficulty Level: Moderate

Explanation

(Option B) Amylase: Function: Amylase is an enzyme that breaks down starch into simpler sugars like maltose.

Optimal pH: Amylase, specifically salivary amylase (also called ptyalin), works best at a neutral to slightly alkaline pH (around pH 7). When food reaches the stomach, the highly acidic environment (with a pH of around 1.5 to 3.5) denatures salivary amylase, thus stopping its action.

(Option A) Lipases: Function: Lipases are enzymes that break down fats into fatty acids and glycerol.

Optimal pH: Lipases work best in slightly alkaline conditions, but some types of lipases, like gastric lipase, can function in the acidic environment of the stomach. Therefore, the action of lipases does not completely come to an end in the acidic pH of the stomach.

(Option C) Maltase: Function: Maltase is an enzyme that breaks down maltose into two glucose molecules.

Optimal pH: Maltase is present in the small intestine, where it works in a neutral to slightly alkaline environment. It is not active in the stomach and thus is not directly affected by the acidic pH of the stomach.

(Option D) Hydrolases: Function: Hydrolases are a broad category of enzymes that catalyze the hydrolysis of various bonds (e.g., ester, glycosidic, peptide).

Optimal pH: This is a general term encompassing many types of enzymes, including those that act in acidic, neutral, and alkaline environments. Therefore, saying the action of hydrolases comes to an end in the stomach is too general and not accurate, as some hydrolases are adapted to function in acidic conditions.

Subject: Chemistry

Topic: Macromolecules

Subtopic: Enzymes

Difficulty Level: Moderate

Alpha-amylase