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A catalyst alters the rate of a chemical reaction by providing an alternative reaction pathway with a lower activation energy, meaning it makes it easier for reactants to reach the transition state and form products, thus significantly increasing the reaction rate without being consumed in the process.

2C\(_2\)H\(_6\)\(_(g)\) + 7O\(_2\)\(_(g)\) → 6H\(_2\)O\(_(g)\) + 4CO\(_2\)\(_(g)\) 2 moles 6 moles 400cm\(^3\) X cm\(^3\) X = \(\frac{{400}\times{6}}{2}\) X = 1200cm\(^3\)

A saturated solution at 30^\circC will normally produce crystals when it is cooled below the saturation point for that specific solute at a lower temperature; this means that crystals will typically begin to form as the solution cools down from 30^\circC, with the exact temperature depending on the solubility curve of the dissolved substance.

Although fats are complex molecules that are made up of fatty acids and glycerol, they are not polymers. Polymers are large molecules made up of many smaller units called monomers that are chemically bonded together. Rubber, starch and proteins are polymers because they have several units of isoprene, glucose and amino acids respectively, chemically bonded together.

The collision theory assumes that the colliding molecules have sufficient energy to be able to overcome the intermolecular forces of attraction and the activation energy barriers, but it does not require that the collision be perfectly elastic. i.e no loss of energy.

While a strong acid dissociates or ionizes completely in water, weak acids only partially ionizes in water.

Esterification reaction is the reaction between an alkanol (alcohol) and an alkanoic acid (carboxylic acid) in the presence of an acid catalyst forms an ester (alkanoate) and water. To produce alkanoates (esters) from alkanols and alkanoic acids, you need to perform esterification, which requires a concentrated acid catalyst (like sulphuric acid) and heat.

Given: m = 22g M.V = 22.4dm\(^3\) V = ? First, calculate the number of moles n, by dividing mass of CO\(_2\) by the molar mass of CO\(_2\), since n = \(\frac{mass}{Molar mass}\) Molar mass of CO\(_2\) = 12 + (2 x 16) = 44g/mol So, n = \(\frac{mass}{Molar mass}\) n = \(\frac{22}{44}\) = 0.5 mole Also recall that number of moles of gases, n = \(\frac{Volume}{Molar Volume}\) n = \(\frac{V}{M.V}\) 0.5 = \(\frac{V}{22.4}\) V = 0.5 X 22.4 V = 11.2 dm\(^3\) Alternatively, Given the mass of CO\(_2\) = 22g Molar mass of CO\(_2\) = 12 + (16X2) = 44g number of moles, n = \(\frac{m}{M}\) = \(\frac{22}{44}\) = 0.5 mole. If 1 mole of CO\(_2\) = 22.4dm\(^3\) 0.5 mole of CO\(_2\) = X dm\(^3\) X = 0.5 x 22.4 = 11.2 dm\(^3\)

Pairs of outermost shell electrons that are not used in bonding are called lone pairs or non-bonding pairs. A lone pair refers to a pair of valence electrons that are not shared with another atom in a covalent bond and is sometimes called an unshared pair or non-bonding pair. Lone pairs are found in the outermost electron shell of atoms.

Isoelectronic species are atoms, ions, or molecules that have the same number of electrons and therefore, the same electronic configuration, even if they are different elements. For \(_8\)X\(^{2-}\) Number of protons = 8, while Number of electrons = 10, because X gains 2 electrons and outnumbers the number of protons. Also, for \(_{10}\)Y, Number of protons = 10, while Number of electrons = 10, because Y has no charge, it is a neutral atom. Hence, the number of protons = Number of electrons =10 Since the number of electrons are the same in both atoms of element X and element Y, even though they are of different elements, they are said to be isoelectronic species. Therefore, \(_8\)X\(^{2-}\) and \(_{10}\)Y are Isoelectronic

Pure water contaminated with quicklime (calcium oxide) will have a highly alkaline pH, significantly above 7. The reason being that quicklime (CaO) reacts vigorously with water to form slaked lime (calcium hydroxide, Ca(OH)₂), a strong base.

The electron configuration of copper (Cu), with atomic number 29, is [Ar] 3d¹⁰ 4s¹ or 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹. Here's a more detailed explanation: Atomic Number:Copper (Cu) has 29 electrons. Following the Aufbau principle, the expected configuration would be 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁹. However, copper exhibits an exception to this rule. A full or half-filled d-orbital is more stable than a partially filled one. Therefore, one electron moves from the 4s orbital to the 3d orbital, resulting in the configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹ or [Ar] 3d¹⁰ 4s¹.

When s and p block elements react, the bond formed is typically ionic or electrovalent, as s-block elements tend to lose electrons to achieve a stable electron configuration, while p-block elements, especially nonmetals, readily gain electrons. These elements(alkali and alkaline earth metals) have low electronegativity and readily lose electrons to form positively charged ions (cations). On the other hand,the P-block elements, especially non-metals like halogens and oxygen, have high electronegativity and readily gain electrons to form negatively charged ions (anions). The electrostatic attraction between these oppositely charged ions results in the formation of an ionic bond or electrovalent bond.

Diamond is the hardest form of carbon. It's also the hardest naturally occurring substance on Earth. Diamond is an allotrope of carbon, meaning it's a variation of carbon's structure. In diamond, carbon atoms are arranged in a tetrahedral structure, with each carbon atom bonded to four other carbon atoms. This structure creates a rigid, three-dimensional network of carbon atoms. Thus,the strong bonds between the carbon atoms make diamond extremely hard.

The strong metallic bonding in aluminum is due to a large number of delocalized electrons that are shared among the metal atoms, creating a "sea" of electrons that strongly attracts the positively charged metal ions. In metallic bonding, the outermost electrons of metal atoms are not bound to any specific atom but are free to move throughout the entire structure. These electrons form a "sea" or "cloud" of negative charge. The positively charged metal ions (cations) are attracted to this "sea" of delocalized electrons, creating a strong electrostatic attraction that holds the metal atoms together.