Question

An element X, which is radioactive and has half life tv2= 20 days. The daughter nuclei formedafter decay of X is 2-6 Y. Calculate the volume of He collected at S.T.P after 40 days if 2 mole ofX is placed in a sealed tube​

Answer 1

Answer:

The answer is 100.8 lit

Explanation:

                   X (parent nuclei) ------>. Y (Daughter nuclei) + 3He

                   Daughter nuclide whose atomic number is 6 less and atomic mass is 12 less than the original element.

t =0                     2 mole                        0 mole                    0 mole               t(1/2)  = 20 days

t (1/2)                 1 mole                         1 mole                    3 mole               2t(1/2) = 40 days

t=2t(1/2)              1/2 mole                     (1+1/2) mole           (3 +3/2) mole

   Mole of He after 2 half-life  = 4.5 mole

  The volume of 4.5 moles of He at STP = 4.5 x 22.4 = 100.8 lit