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Isotope \(^{65}X_{30}\) (with a mass of 65 and an abundance of 60%): Relative mass contribution = (65 * 60%) = 39.00 Isotope \(^{66}X_{30}\) (with a mass of 66 and an abundance of 40%): Relative mass contribution = (66 * 40%) = 26.40 Now, add the relative mass contributions of both isotopes: Relative atomic mass \(A_r\) = 39.00 + 26.40 = 65.40 So, the relative atomic mass of element X is 65.40. The correct option is: 65.40

The rate of reaction is proportional to the number of effective collisions. This means that if the number of collisions increases, the rate of reaction will also increase. These successful collisions are known as effective collisions. The rate of reaction is directly proportional to the number of effective collisions between reactant molecules. In other words, the more frequent and successful the collisions, the faster the rate of the reaction.

Sodium is an alkali metal, and its atomic number is 11. This means that it has 11 electrons, and its electron configuration is \(1s^2 2s^2 2p^6 3s^1\). The valence electrons are the electrons in the outermost shell, which in this case is the 3s orbital.

Applied chemistry refers to the practical application of chemical principles and techniques to solve real-world problems and create useful products. Petrochemistry is a branch of applied chemistry that deals specifically with the chemical processes and transformations involved in the extraction, refining, and processing of petroleum and its derivatives

In \(Cl_2\), the two chlorine atoms are identical and have the same electronegativity. Since both atoms have the same electronegativity, the electrons in the covalent bond are shared equally, resulting in a non-polar covalent bond. The molecule does not have a significant separation of charge and lacks a permanent dipole moment.

The reduction half equation for the given reaction is: \(Cu^{2+}_{(aq)} + 2e^- → Cu_{(s)}\) In the overall reaction, copper(II) ions (\(Cu^{2+})\) gain two electrons (2e^-) and get reduced to form solid copper (Cu) metal. This is the reduction half-reaction in the redox reaction between zinc (Zn) and copper(II) sulfate (\(CuSO_4)\).

\(H_2SO_4\) and \(CaCl_2\) are not suitable for drying ammonia gas because they react with the gas. Ammonia is a basic gas, and both \(H_2SO_4\) and \(CaCl_2\) are acidic. When these two substances react, they form salts that contain ammonia. This can contaminate the ammonia gas and make it unusable. In addition, \(H_2SO_4\) is a corrosive substance, and \(CaCl_2\) can be harmful to breathe in. Therefore, it is not safe to use these substances to dry ammonia gas.

The term "isoelectronic" comes from the Greek words "iso" meaning "equal" and "electron" meaning "electron". Isoelectronic species are atoms, molecules, or ions that have the same number of electrons. have the same number of electrons because they have the same electron configuration. The electron configuration of an atom is the arrangement of electrons in the atom's orbitals. The electron configuration of an atom determines the chemical properties of the atom.

The rate of diffusion of a gas is inversely proportional to the square root of its molar mass (Graham's law). This means that gases with a higher molar mass will diffuse more slowly than gases with a lower molar mass. Given the molar masses of the gases in the options, Oxygen (O=16.0) has the highest molar mass and therefore the lowest rate of diffusion

The chemical formula for sodium tetraoxosulphate (VI) is \(Na_2SO_4\). It is also known as sodium sulfate. This compound does not have any water molecules as part of its crystal structure, making it anhydrous. So, it is an example of a crystalline substance that does not possess water of crystallization.

Phenolphthalein is an indicator that is commonly used in acid-base titrations. It is colorless in acidic solutions (pH below 8.2) and turns pink or magenta in alkaline solutions (pH above 10). In the titration of ethanoic acid (acetic acid) with sodium hydroxide (a strong base), the pH will change from acidic to alkaline as the acid is neutralized by the base

Vapour density = Relative molar mass / 2 Vapour density = 30 / 2 = 15 Therefore, the vapour density of the gaseous hydrocarbon is 15.

Thermal cracking is a process used in the petroleum industry to break down long-chain alkanes (hydrocarbons) into smaller, more useful hydrocarbons. It involves the decomposition of high-molecular-weight hydrocarbons, such as heavy crude oil fractions or long-chain alkanes, into lower-molecular-weight hydrocarbons, like smaller alkanes and alkenes. During thermal cracking, high temperatures and sometimes pressure are applied to the feedstock (such as crude oil or natural gas) to initiate the decomposition reactions.

Amount (in moles) = Molarity \times Volume Amount (in moles) = 0.20 mol/dm³ \times 100.0 cm³ / 1000 cm³/dm³ = 0.020 moles Now, we can calculate the mass using the formula: Mass = Amount \times Molar Mass Mass = 0.020 moles \times 40.0 g/mol = 0.80 g So, the correct answer is:0.80 g

1 Faraday of electricity is equal to the charge of 1 mole of electrons, which is 96,485 coulombs. The reduction of copper(II) ions in solution to copper metal requires 2 electrons per ion, so 1 Faraday of electricity will deposit 0.5 moles of copper. 1 Faraday * (2 electrons/Cu ion) / (1 mole electrons/96,485 coulombs) * (1 mole Cu/2 electrons) = 0.5 moles Cu