Consider a 15.60g sample of 131I, which has a half-life of 8.02 days.
a. How much of the sample (in grams) will remain after 16.04 days?
b. How much of the sample will remain after 16.04 hours?
a)
half - life = 8.02 days
rate constant k = 0.693 / t1/2
= 0.693 / 8.02
= 0.0864 day-1
rate constant k = 1/t ln (Ao / At)
0.0864 = 1/ 16.04 ln (15.60 / At)
At = 3.90 g
mass of sample remain = 3.901 g
b)
time = 16.04 hours = 0.6683 days
rate constant k = 1/t ln (Ao / At)
0.0864 = 1/ 0.668 ln (15.60 / At)
At = 14.72 g
mass of sample remain = 14.72 g
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