Even though so much energy is required to form a metal cation with a 2+ charge, the alkaline earth metals form halides with the general formula MX2, rather than MX. (a) Use the following data to calculate of MgCl: Page 403 (b) Is MgCl favored energetically relative to Mg and Cl2? Explain. (c) Use Hess’s law to calculate ΔH° for the conversion of MgCl to MgCl2 and Mg ( of MgCl2 = −641.6 kJ/mol). (d) Is MgCl favored energetically relative to MgCl2? Explain.

answer : (a) volume of the gas = 8.67 ×   l

                (b) second virial coefficient b = -1.21226 l/mole

solution :   given,     t = 300k

                                p = 20atm

                                z = 0.86

                                n = 8.2 mmoles = 8.2 × moles

                                r =   0.082 l atm/k/mol

        find,     (a) volume of gas   and (b) second virial coefficient b at 300k.

formula used :            

                          and            

(a)            

                    = \times 0.082\times 300}{20}[/tex]

                    = 8.67 ×   l

(b)      

                    = (0.00867-1) × 8.659

                    = - 8.5839 l/mole