HALF LIFES CHEMISTRY PROBLEMS 1)How much of a 888lb sample of Radium-189 Remains after 3 half Lives?

2)If you start with 200g or Uranium-282,How much will remain of 4 half lives?

3)How much of a 750 gram sample of 42K is left after 12.4 hours?

4)How much of an 88 gram sample of 232Th of remains after 4.2x10^10 years?

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