Question

A `0.2 mL` sample of a solution containing `1.0xx10^(-7)` curie of `._(1)^(3)H` is injected to the blood stream of an animal. After sufficient time for circulatory equilibrium to be esalablished, `0.10 mL` of blood is found to have an activity of `20 dp m`. Calculate teh volume fo blood in animal, assuming no change in activity of sample during circulatroy equilibrium.

Answer 1

Let volume of blood be `V mL`.
Thus total volume `= V + 0.2 mL` after injection of sample `0.1 mL` sample has rate `=(20)/(60)dps`
`:.(V+0.2)mL `sample has rate `= (20xx(V + 0.2))/(60xx0.1)` dps
Since rate is constant, thus
`(20xx(V + 0.2))/(60xx0.1) = 1.0 xx 10^(-7) xx 3.7xx10^(10)` dps
`V = 1109.8 mL`