(answered) – 1) An unknown gas, X 2 (g), which behaves much like N 2 (g)DescriptionSolution downloadThe Question1) An unknown gas, X2(g), which behaves much like N2(g)?(N?N), is analysed and the following enthalpies of formation are obtained:Gas?H?fX(g) 474 kJ/molH(g) 217 kJ/molX2H4(g) -23 kJ/molWe also know that the X-H bond energy is 417 kJ/mol.?Use this information to estimate the X-X (single-)bond energy in the X2H4?molecule.Give your answer to the nearest 1 kJ/mol.2)?Suppose a chemist discovers a new metallic element and names it “Xegeum” (Xg).?Xg exhibits chemical behaviour similar to an?alkaline earth.?Xg(s) +? Cl2(g) ?? XgCl2(s)Lattice energy for XgCl2 -2060 kJ/molFirst Ionization energy of Xg ?490 kJ/molSecond Ionization energy of Xg ?882 kJ/molElectron affinity of Cl -348.7 kJ/molBond energy of Cl2 ?239 kJ/molEnthalpy of sublimation (atomization) of Xg???? ?160 kJ/molUse the above data to estimate ?H?f?for Xegeum chloride.3)?For each pair, indicate which would have the?lattice energy?of?lesser magnitude.?MgS??MgSe??SrO??NaI??BaO??SrO??CaTe??CaO??NaBr??NaI4)?Coulomb’s Law yields an expression for the energy of interaction for a pair of point charges.V is the energy (in J) required to bring the two charges from infinite distance separation to distance?r?(in nm).??Q1?and?Q2?are the charges in terms of electrons.??(i.e. the constant in the above expression is 2.31?10-19?J nm?electrons-2)For a group of “point” charges (e.g. ions) the total energy of interaction is the sum of the interaction energies for the individual pairs.?Calculate the energy of interaction for the arrangement of ions shown in the diagram below.?d = 0.535 nm.5)?Order each of the following sets of five atoms and ions according to?decreasing?size.(i.e. “1” largest and “5” smallest)?Mg2+??Br-??P?Cs?N6)?Consider the following statements and determine which are true and which are false.- NO3-?has only two resonance Lewis structures.?- Selenium tetrafluoride (SeF4) is a non-polar molecule.?- The?formal charge?on an atom in a molecule (or molecular ion) can be calculated as:?(the number of valence electrons on a free atom)?minus?(half the number of electrons in bonds to that atom)?minus?(the number of unshared electrons assigned to the atom in the molecule)?- KrF4?has a tetrahedral structure.?- Silane (SiH4) is a polar molecule.?- KrF4?is a non-polar molecule.