1. Suppose a patient is given a certain amount of iodine -131 as part of a diagnostic procedure for a thyroid disorder. Iodine -131 undergoes first order radioactive decay. Given that the half-life of radioactive iodine-131 of 8.0 days, what fraction of the initial iodine 131 would be present in a patient after 24 day if none of it were eliminated through natural body processes?
2. The reaction 2HI(g) -> H2(g) + I2(g) has the rate law, Rate = k[HI]2, with k= 0.079 L mol-1 s-1 at 508°C. What is the half-life for this reaction at this temperature when the initial HI concentration is 0.10 M?
3.Radioactive decay follows a first order kinetics. The half-life of radioactive radium is 1600 years. Calculate the time taken for the reactivity of a sample of radium to decrease to 12% of its original value.
Please explain to me step by step
Thank you
2. The reaction 2HI(g) -> H2(g) + I2(g) has the rate law, Rate = k[HI]2, with k= 0.079 L mol-1 s-1 at 508°C. What is the half-life for this reaction at this temperature when the initial HI concentration is 0.10 M?
3.Radioactive decay follows a first order kinetics. The half-life of radioactive radium is 1600 years. Calculate the time taken for the reactivity of a sample of radium to decrease to 12% of its original value.
Please explain to me step by step
Thank you
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1) T1/2 = 8 days, Total time = 24 days.
Number of half-life = 24/8 = 3
Fraction of remaining = 1(original fraction) x (1/2)^n, where n = number of half-life
Therefore = 1x1/8 = 1/8
2) Can't help you.. Sorry
3) Fraction remaining = 12/100 = 3/25, Half life = 1600
3/25 = 1x(1/2)^n
1/8.33333 = (1/2)^n
n= approx. 3.06
Total time = 3.06 x 1600 years = 4896 years
Number of half-life = 24/8 = 3
Fraction of remaining = 1(original fraction) x (1/2)^n, where n = number of half-life
Therefore = 1x1/8 = 1/8
2) Can't help you.. Sorry
3) Fraction remaining = 12/100 = 3/25, Half life = 1600
3/25 = 1x(1/2)^n
1/8.33333 = (1/2)^n
n= approx. 3.06
Total time = 3.06 x 1600 years = 4896 years