During nuclear explosion, one of the products is \(^{90}Sr\) with half-life of 28.1 years. If 1µg of \(^{90}Sr\) was absorbed in the bones of a newly born baby instead of calcium, how much of it will remain after 10 years and 60 years if it is not lost metabolically.
\(k = \frac {0.693}{t_{1/2}} = \frac {0.693}{28.1} \ Y^{-1}\)
Here,
It is known that,
\(t = \frac {2.303}{k} log \ \frac {[R]_0}{[R]}\)
\(10 = \frac {2.303}{0.693/28.1} log \ \frac {1}{R}\)
\(10 = \frac {2.303}{0.693/28.1} (-log \ [R])\)
\(log \ [R] =\frac { 10\times 0.693}{2.303\times28.1}\)
\([R] = antilog \ (-0.1071)\)
\([R] = antilog (\bar1.8929)\)
\([R] = 0.7814 \ µg\)
Therefore, 0.7814 µg of \(^{90}Sr\) will remain after 10 years.
\(t = \frac {2.303} {k}log \ \frac {[R]_0}{[R]}\)
\(60 = \frac {2.303}{0.693/28.1} log \ \frac {1}{R}\)
\(60 = \frac {2.303}{0.693/28.1} (-log \ [R])\)
\(log \ [R] =\frac { 60\times 0.693}{2.303\times28.1}\)
\([R] = antilog \ (-0.6425)\)
\([R] = antilog \ (\bar1.3575)\)
\([R] = 0.2278\ µg\)
Therefore, 0.2278 µg of \(^{90}Sr\) will remain after 60 years.
Chemical kinetics is the description of the rate of a chemical reaction. This is the rate at which the reactants are transformed into products. This may take place by abiotic or by biological systems, such as microbial metabolism.
The speed of a reaction or the rate of a reaction can be defined as the change in concentration of a reactant or product in unit time. To be more specific, it can be expressed in terms of: (i) the rate of decrease in the concentration of any one of the reactants, or (ii) the rate of increase in concentration of any one of the products. Consider a hypothetical reaction, assuming that the volume of the system remains constant. R → P
Read More: Chemical Kinetics MCQ