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Propane, C\(_3\)H\(_8\) reacting with chlorine ((Cl\(_2\)) in sunlight is a free radical substitution reaction, also known as photochemical chlorination, where sunlight (UV light) provides energy to break the \(Cl-Cl\) bond, allowing chlorine atoms to replace hydrogen atoms on the propane molecule, forming chloropropanes and hydrogen chloride (HCl).

During the electrolysis of brine (sodium chloride solution), hydrogen gas (\(H_{2}\)) is produced at the cathode (negative electrode) because water molecules are more easily reduced than sodium ions (\(Na^{+}\)), forming hydrogen gas and hydroxide ions (\(OH^{-}\)). This process also generates sodium hydroxide (caustic soda) and chlorine gas at the anode, making it a crucial industrial process.

In the Orsat apparatus for flue gas analysis, ammoniacal cuprous chloride, CuCl\(_2\) is specifically used to absorb CO. The CO acts as a Lewis base and forms a soluble coordination complex or adduct with the copper(I) ions. A. \(\text{H}_{2}\) (Hydrogen) and C. \(\text{N}_{2}\) (Nitrogen) are generally unreactive with the solution and remain after the absorption process. These are typically determined by difference in a gas analysis experiment. D. \(\text{CO}_{2}\) (Carbon dioxide) is absorbed by a different solution, typically an alkaline solution like potassium hydroxide (\(\text{KOH}\)), in the Orsat apparatus.

Water exists as a liquid at room temperature primarily due to the presence of strong hydrogen bonds between adjacent water molecules. Hydrogen bonds are a strong type of intermolecular force (force between molecules) that cause water molecules to attract each other and resist separation into a gas phase at typical room temperatures. A. electrovalent bond (ionic bond) is a strong force that exists between ions, like in table salt (NaCl), not within or between water molecules. Water is a polar covalent compound. B. covalent bond is the strong intramolecular force that holds the hydrogen and oxygen atoms together within a single water molecule (\(\text{H}_{2}\text{O}\)). The existence of the molecule itself depends on the covalent bonds, but the liquid state (how molecules interact with each other) is due to the intermolecular hydrogen bonds. C. van der waals forces are weaker intermolecular forces present in all molecules. While present, they are much weaker than hydrogen bonds. If only van der Waals forces were present, water would be a gas at room temperature, similar to other hydrides like hydrogen sulfide (\(\text{H}_{2}\text{S}\)).

Reforming, specifically catalytic reforming, is a petroleum refining process used to convert low-octane, straight-chain or cyclic hydrocarbons into high-octane aromatic hydrocarbons. This process improves the quality of gasoline (petrol) and involves dehydrocyclization (cyclization and dehydrogenation). Cyclohexane (\(\text{C}_{6}\text{H}_{12}\)) is a cycloalkane that is converted into the aromatic compound benzene (\(\text{C}_{6}\text{H}_{6}\)) during this process, with the release of hydrogen gas (\(\text{H}_{2}\)). This is a key example of a reforming reaction.The general reaction is: \(\text{C}_{6}\text{H}_{12}\rightarrow \text{C}_{6}\text{H}_{6}+3\text{H}_{2}\). A. hexene to hexane is a hydrogenation reaction (addition of hydrogen to an alkene to form an alkane), not reforming. Reforming typically involves dehydrogenation (removal of hydrogen) and cyclization. C. hexane to carbon(IV)oxide and water vapour is the complete combustion of hexane, which produces energy but is not a petroleum refining process for product reformation. D. hexane to butane and ethane is an example of cracking, a process that breaks down larger hydrocarbons into smaller, more valuable ones, which is distinct from reforming. The correct answer is option B

Carbon(II)oxide, (CO), is primarily a product of the incomplete combustion of carbon-containing fuels such as natural gas, coal, wood, and oil. When there is an inadequate supply of oxygen during burning, CO is produced instead of the less harmful carbon dioxide (CO₂). A. photochemical smog is a type of air pollution resulting from the reaction of sunlight with nitrogen oxides and volatile organic compounds; carbon monoxide is involved in the complex cycles of reactions, but it is a primary pollutant produced by combustion, not the source of the smog itself. The primary components of photochemical smog are secondary pollutants like ozone and peroxyacetyl nitrate (PAN). B. respiration is a natural process in living organisms that produces carbon dioxide (CO₂) as a byproduct, not carbon monoxide (CO). CO₂ is an essential component of the carbon cycle and not typically considered an air pollutant in the same toxicological sense as CO (though it is a major greenhouse gas). D. decomposition of sewage involves biological processes that can produce various gases, such as methane (CH₄) or hydrogen sulfide, but not significant amounts of carbon monoxide as an air pollutant. The correct option is C. combustion of fuel.

According to Le Chatelier's principle, changes in pressure only affect the position of equilibrium in gaseous reactions if there is a difference in the total number of moles of gas between the reactant and product sides of the balanced chemical equation. In the scenario described, there is "no change in volume in a gaseous reaction," which implies that the total number of moles of gaseous reactants is equal to the total number of moles of gaseous products. For example, H\(_2\)\(_{(g)}\) + I\(_2\)\(_{(g)}\) ⇌ 2HI\(_{(g)}\). When the number of moles of gas is the same on both sides, both the forward and backward reaction rates increase or decrease equally in response to a pressure change, so the equilibrium position remains unchanged.

Sodium chloride (\(\text{NaCl}\)) is a salt formed from the neutralization reaction of a strong acid (hydrochloric acid, \(\text{HCl}\)) and a strong base (sodium hydroxide, \(\text{NaOH}\)). When it dissolves in water, neither the sodium ions nor the chloride ions undergo significant hydrolysis (reaction with water). As a result, the concentrations of \(\text{H}^{+}\) and \(\text{OH}^{-}\) ions in the water remain essentially unchanged, and the solution maintains a neutral pH of approximately 7.

The spontaneity of a reaction is determined by the Gibbs free energy change (\(\Delta G\)), given by the equation:\(\Delta G=\Delta H-T\Delta S\)For a reaction to be spontaneous, \(\Delta G\) must be negative (\(\Delta G<0\)). For the given reaction: Entropy Change (\(\Delta S\)): The reaction involves the conversion of one mole of gas into one mole of solid and one mole of gas. The formation of a highly ordered solid from a less ordered gas results in a decrease in entropy, so \(\Delta S\) is negative (\(\Delta S<0\)).Enthalpy Change (\(\Delta H\)): Since the entropy change is negative, the term \(-T\Delta S\) is positive. For \(\Delta G\) to be negative (spontaneous), the \(\Delta H\) term must be sufficiently negative to overcome the positive \(-T\Delta S\) term. Therefore, the reaction must be exothermic, meaning \(\Delta H\) is negative (\(\Delta H<0\)). Therefore, for this specific reaction to be spontaneous, the enthalpy change (\(\Delta H\)) must be negative.

The reaction provided shows ethanol (\(\text{C}_{2}\text{H}_{5}\text{OH}\), an alcohol) reacting with ethanoic acid (\(\text{CH}_{3}\text{COOH}\), a carboxylic acid) to produce ethyl ethanoate (\(\text{CH}_{3}\text{COOC}_{2}\text{H}_{5}\), an ester) and water (\(\text{H}_{2}\text{O}\)). The formation of an ester and water from an alcohol and a carboxylic acid is defined as an esterification reaction. This is also a type of condensation reaction, where two molecules combine to form a larger one, eliminating a small molecule (water) in the process. A. condensation: While esterification is a type of condensation reaction, "esterification" is the specific name for the reaction forming an ester. B. fermentation: Fermentation is the process of breaking down organic molecules, such as glucose into ethanol and carbon dioxide, in the absence of oxygen, usually with microorganisms. It is not the process shown in the reaction. D. hydrolysis: Hydrolysis is the reverse reaction, where an ester breaks down into a carboxylic acid and an alcohol by reacting with water. The correct answer is option C - Esterification

To identify the specific acid and alcohol reactants, we can reverse this process by adding water back to the ester molecule: The part with the carbonyl group (\(\text{COO}\)) comes from the carboxylic acid. The \(\text{CH}_{3}\text{CH}_{2}\text{COO}\) part corresponds to propanoic acid (\(\text{CH}_{3}\text{CH}_{2}\text{COOH}\)).The alkyl group attached to the oxygen atom (\(\text{O}\)) comes from the alcohol. The \(\text{CH}_{2}\text{CH}_{3}\) group corresponds to ethanol (\(\text{CH}_{3}\text{CH}_{2}\text{OH}\)). Thus, the reaction that forms ethyl propanoate is between propanoic acid and ethanol. A. ethanol and ethanoic acid: These reactants would form ethyl ethanoate (\(\text{CH}_{3}\text{COOCH}_{2}\text{CH}_{3}\)), not ethyl propanoate. B. propanol and propanoic acid: These reactants would form propyl propanoate (\(\text{CH}_{3}\text{CH}_{2}\text{COOCH}_{2}\text{CH}_{2}\text{CH}_{3}\)), which has a three-carbon chain on both sides of the ester link, unlike the given structure. C. propanol and ethanoic acid: These reactants would form propyl ethanoate (\(\text{CH}_{3}\text{COOCH}_{2}\text{CH}_{2}\text{CH}_{3}\)), which also does not match the given structure. The correct option is D. propanoic acid and ethanol.

Stainless steel is widely used for making cutlery (knives, forks, spoons, and other utensils) due to its excellent properties. These properties include corrosion resistance (it doesn't rust easily), durability, hygiene, and non-reactive properties that make it safe for contact with food. B. permanent magnets: Permanent magnets are typically made from specific ferromagnetic alloys like Alnico, not stainless steel. Most common grades of stainless steel (austenitic) are non-magnetic. C. rock crushers: Rock crushers require extremely hard and wear-resistant materials to withstand the abrasive forces involved. While some specialized, high-strength stainless steel grades might be used in certain industrial contexts, the primary material for heavy-duty rock crushing components is usually manganese steel or other extremely tough alloys designed for high impact and abrasion, not standard stainless steel. D. bridges: While stainless steel can be used in certain components in bridge building for its corrosion resistance, especially in harsh environments, the primary structural material for most large bridges is typically structural steel (carbon steel) or concrete. The general use for "bridges" is less specific and less common than its use in cutlery manufacturing. The correct answer is option A - Cutlery

Basicity refers to the number of replaceable hydrogen ions (H\(^+\)) an acid molecule can furnish in a solution. The basicity of oxalic acid (C\(_2\)H\(_2\)O\(_4\)) is 2, meaning it's a dibasic acid because each molecule can donate two protons (H\(^+\)) when ionized in water, forming two replaceable hydrogen atoms and reacting with two moles of hydroxide ions, allowing it to form normal salts like K\(_2\)C\(_2\)O\(_4\).

The enzymatic conversion of glucose to ethanol is a biochemical process called fermentation, primarily catalyzed by the enzyme complex zymase, found in yeast, breaking down sugar into ethanol and carbon dioxide, crucial for brewing, baking, and biofuels. The overall chemical equation for the conversion of glucose to ethanol via fermentation is C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂, where one molecule of glucose (C₆H₁₂O₆) breaks down into two molecules of ethanol (C₂H₅OH) and two molecules of carbon dioxide (CO\(_2\)). Glucose polymerization links many glucose monomers (units) into long chains (polymers) like starch, cellulose, and glycogen, forming essential carbohydrates for energy storage (starch/glycogen) or structure (cellulose). The hydrogenation of glucose is a catalytic process that adds hydrogen to its carbonyl group, reducing it to a primary alcohol and converting the sugar into sorbitol, a widely used sugar alcohol. Saponification is the chemical process where fats or oils react with a strong alkali (like sodium or potassium hydroxide) to produce soap (a fatty acid salt) and glycerol.

Gold does not require complex extraction because it's a noble metal that is highly unreactive (inert), allowing it to be found in its pure, elemental (native) form in nature as nuggets or flakes, rather than locked in compounds, making options B and C correct, but C is the direct reason for not needing extraction from ore. Therefore, while being precious (A) and neutral (D, technically, as it's an element), the key reason it's found easily is its inert nature (B) and presence as a free element (C).