— Physical Chemistry Chemistry Question
Radioactivity of Iodine and Nuclear Equations
The half-life of 131 I is 8 days. If a freshly prepared solution of 131 I has a concentration of 0.1 mol dm -3,
(i) what will be the concentration of 131 I after 2 half-lives?
(ii) what will be the concentration of 131 I after 40 days?
Model Answer
(i) After 2 half-lives, the remaining concentration of I-131 will be as follows:
[I-131] [VISUAL]
(ii) After 40 days which is equal to 5 half-lives, the remaining concentration of I-131 will be as follows:
[I-131] [VISUAL]
Identify X in each of the following nuclear equations:
(i) X + -
(ii) + X
(iii) + X
(iv) X +
(v) + X +
(vi) X +
(vii) + + X + 4
(viii) + X +
Model Answer
21.2 (i) (ii) or + (iii) (iv)
(v) (vi) (vii) (viii) or
[Note: The specific nuclide notation symbols, sub/superscripts, and reaction components are missing or garbled in the source text extraction.]