Lithium has two naturally occurring isotopes, 6 Li and 7 Li . The average atomic mass of lithium is 6.941. Which of the following statements concerning the relative abundance of each isotope is correct ? A) The abundance of 7 Li is greater than 6 Li. B) The abundance of 7 Li is less than 6 Li. C) The abundance of 6 Li is equal to the abundance of 7 Li. D) Not enough data is provided to determine the correct answer. E) Based on the atomic mass, only 7 Li occurs naturally.

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