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Water gas is produced when steam is passed over red-hot carbon. Water gas has the chemical formula as CO + H\(_2\) The chemical reaction for the production of water gas is C(s) + H\(_2\)O(g) → CO(g) + H\(_2\)(g).

Sulphur(IV) Oxide bleaches coloured substances through the process of reduction. It removes oxygen from coloured substances and makes them colourless, but this change is reversible as atmospheric oxygen can re-oxidize the colourless products, causing the colour to return. In order to get a permanent bleaching action, Chlorine is recommended. This is because chlorine reacts with water to produce nascent oxygen, which acts as an oxidizing agent and permanently oxidizes coloured substances.

Carbon is tetravalent because its 2s and 2p atomic orbitals hybridize to form four sp³ hybrid orbitals. Carbon has four valence electrons, so it can form a maximum of four bonds. When a carbon atom's 2s and 2p orbitals hybridize, they form four equivalent sp³ hybrid orbitals. Each sp³ orbital can form a sigma bond, resulting in a tetrahedral geometry. Carbon's tetravalency, meaning its ability to form four bonds, is explained by the concept of sp3 hybridization. This hybridization involves the mixing of one s orbital and three p orbitals to create four equivalent sp3 hybrid orbitals. This allows the carbon atom to form four single bonds, as seen in methane (CH\(_4\)).

Aluminum hydroxide is used in the dyeing industry as a mordant. A mordant is a substance that helps dyes stick to fabrics by forming a complex with the dye that attaches to the fabric. In dyeing, salt's primary function is to enhance dye absorption and fixation, while a mordant's role is to create a chemical bond between the dye and the fiber, improving colourfastness and potentially altering the final shade. Salts often act as a dyeing promoter, increasing dye exhaustion from the dye bath. Mordants, on the other hand, are typically metallic salts or other substances that form a stable complex with both the dye and the fiber, ensuring the color remains vibrant and stable.

The most common way to prepare an alloy is to melt metals together and then pour the mixture into a mold to solidify. This method is called melting and mixing. Alloys are created by combining two or more metallic elements, or sometimes a metal with a non-metal, in a solid solution, compound, or mixture. The process typically involves melting the base metal and then adding the alloying agents. Mixing is easier in the liquid state than in the solid state, so most alloys are made by melting the base metal. Electroplating primarily adds a thin coating of metal to a substrate, not creating a true alloy with the base material. It can be used to enhance surface properties like corrosion resistance or wear resistance, but not to create a new alloy with specific metallurgical properties throughout the material. While welding can join different metals, it's primarily used for joining existing pieces of metal, not for creating alloys from scratch. While some methods involve processing metal oxides to create alloys, melting and mixing the metals directly is generally more common and efficient for most alloy production.

Transition metals have variable oxidation states because their valence electrons are in the d-orbitals with similar energies, allowing them to be used for bond formation in multiple ways. Transition metals have partially filled d-orbitals in their outer electron shell.

Sodium metal is always kept under oil, typically kerosene, because it is a highly reactive metal that readily reacts with oxygen and moisture in the air, potentially causing a fire if exposed directly; by submerging it in oil, this contact is prevented and the metal remains stable. Also, sodium metal reacts vigorously with oxygen and carbon dioxide in air as it is a highly reactive metal that can catch fire and burn when exposed to air. It reacts vigorously with air, especially in the presence of moisture. Sodium is a highly reactive metal that can ignite spontaneously in air. Option D would have been also correct but option C is more detailed and all encompassing because in air, we have O\(_2\). CO\(_2\). as well as water vapour. Therefore, option C is the correct answer In summary, while sodium reacts vigorously with all three (oxygen and water), preventing the reaction with oxygen and moisture is the most important reason for storing it under oil because these reactions are more exothermic and potentially dangerous.

Oxyacetylene flames are used for welding iron because they produce a very high temperature that melts the iron. The flame produced by oxyacetylene is very hot, reaching temperatures of around 3,100^\circC. This is hot enough to melt steel, which has a melting point of over 1,500^\circC.

The alkyl group is a type of functional group that has a carbon and hydrogen atom present in its structure. The general formula for an alkyl group is C\(_n\)H\(_{2n+1}\), where n represents a number or integer.

There are three isomers of C\(_5\)H\(_{12}\). They include n-pentane , 2 - methyl butane and 2,2-dimethylpropane.

Substitution reactions are a characteristic reaction of alkanes because they are saturated compounds with only single bonds. This means that hydrogen atoms in an alkane can be easily replaced by other atoms or groups.

Copper(I) chloride does not confirm the presence of a triple bond, rather it is ammoniacal cuprous chloride (Cu(NH\(_3\))\(_2\)ClOH)(CuCl) that can be used to distinguish between double and triple bonds in unsaturated hydrocarbons. The test involves reacting the compound with ammoniacal cuprous chloride to see if a red precipitate forms. If a red precipitate forms, the compound is an alkyne and contains at least one triple bond. If no precipitate forms, the compound is an alkene and contains at least one double bond. To confirm the presence of a triple bond, you can use bromine water (Br₂) or Baeyer's reagent (alkaline potassium permanganate), both of which react with unsaturated bonds (double or triple) by addition reactions, causing the colour of the reagent to disappear.

Vulcanization can cause isomerization of a double bond. This isomerization is a type of stereoisomerism, which is a change in the relative positions of atoms in a molecule. Vulcanization is a process that hardens rubber by forming cross-links between polymer chains.

The decarboxylation reaction of acetic acid (CH\(_3\)COOH) is a process that removes the carboxyl group (−COOH) and replaces it with a hydrogen atom. The reaction produces methane (CH\(_4\)), carbon dioxide (CO\(_2\)).

Dehydration of ethanol is the process of removing water from ethanol to produce ethene, CH\(_2\)=CH\(_2\). This process can be achieved by heating ethanol with concentrated sulphuric acid H\(_2\)SO\(_4\)