Question Library

N\(_{2(g)}\) + 3H\(_{2(g)}\) ⇔ 2NH\(_{3(g)}\) In the Haber process, the forward reaction is exothermic and the backward reaction is endothermic. If the temperature is decreased, the yield from the exothermic direction is increased i.e. the forward reaction is increased.

The definition of enthalpy change is \DeltaH = \DeltaU + Pex(\DeltaV) The enthalpy change is zero because both terms on the right are zero in free expansion of an ideal gas. There is no external pressure in a free expansion, so P (ex) = 0. And the internal energy change, \DeltaU of free expansion in a closed system is zero since no inter molecular forces have to be overcome. The temperature remains constant and no heat is absorbed or released.

Alkanones also known as ketones have the general formula R\(_2\)CO

Bacteria of the genus Propionibacterium produce propionic acid (Propanoic Acid) as the end-product of their anaerobic metabolism. This class of bacteria is commonly found in the stomach of ruminants and the sweat glands of humans, and their activity is partially responsible for the odour of both Swiss cheese and sweat.

In electro-valency the oxidation number of the participating metal increases.

In a neutral atom, the atomic and ionic radius is the same, but many elements exist as anions or cations. If the atom loses its outermost electron (positively charged or cation), the ionic radius is smaller than the atomic radius because the atom loses an electron energy shell. Yes ionic radius is only less than atomic radius for a metal.

Calcium trioxocarbonate (IV) = CaCO\(_3\) Percentage of Oxygen = \(\frac{\text{Molar mass of 3O}}{\text{Molar mass of} CaCO_3}\) \times 100% Percentage of Oxygen = \(\frac{(3 \times 16)}{(40 + 12 + 48)}\) x 100% Percentage of Oxygen = \(\frac{48}{100}\) x 100% Percentage of Oxygen = 48%

Bronze is an alloy consisting primarily of copper, commonly with about 12% tin and often with the addition of other metals (such as aluminium, manganese, nickel or zinc) and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon.

Molecular mass = Vapour Density x 2 Vapour Density = \(\frac{\text{Molecular Mass}}{2}\) Where Molecular mass = 98g/mol Vapour Density = \(\frac{98}{2}\) Vapour Density = 49g/mol

The periodic number table is arranged in order of atoms increasing atomic number

H \(_2\) S + Cl \(_2\) → 2HCl + S Please note: substance oxidized or reduced are always the reactants. So, one can easily cross out the two products. Reduction is 1. Addition of hydrogen 2. Removal of Oxygen 3. Addition of Electron Oxidation is 1. Removal of hydrogen 2. Addition of hydrogen 3. Removal of Electron From the question we can see that H was added to Cl in the product, thereby making hydrogen to be removed from S in the reactant hence S is oxidized as a result of the removal of hydrogen and Cl \(_2\) has been reduced due to addition of hydrogen. Cl \(_2\) is reduced

Between the five main minerals found in clay, kaolinite is the most common. Kaolinite holds the chemical composition A\(l_2\) S\(i_2\)\(O_5\)(OH)\(_{4}\) and is an aluminum silicate material with a low “shrink-swell” capacity. It is a soft, white mineral but is often colored orange or red by iron oxide found in the soil.

Cracking is the breakdown of a large alkane into smaller, more useful alkenes. Simply put, hydrocarbon cracking is the process of breaking a long-chain of hydrocarbons into short ones. This process might require high temperatures and high pressure.

permutit water softener can be regenerated by washing the spent resin with brine( saturated sodium chloride solution). The solution ions replace the calcium or magnesium ions present in it. \(CaR_{2(s)}\) + 2\(NaCl_{aq}\) → \(CaCl_{2(aq)}\) + 2\(NaR_{2(s)}\)

No expanded working has been attached for this question yet. The verified answer is Option D.