Question

At 8:00 A.M., a patient receives a 1.1-μg dose of I-131 to treat thyroid cancer. Part...

At 8:00 A.M., a patient receives a 1.1-μg dose of I-131 to treat thyroid cancer.

Part A

If the nuclide has a half-life of 8.0 days, what mass of the nuclide remains in the patient at 4:00 P.M. the next day? (Assume no excretion of the nuclide from the body.)

Express your answer using two significant figures.

m =   μg  

Homework Answers

Answer #1

Given:

Half life = 8.0 days = 8.0*24 hours = 1.92*10^2 hours

use relation between rate constant and half life of 1st order reaction

k = (ln 2) / k

= 0.693/(half life)

= 0.693/(1.92*10^2)

= 3.609*10^-3 hours-1

we have:

[A]o = 1.1 ug

t = 32 hours

k = 3.609*10^-3 hours-1

use integrated rate law for 1st order reaction

ln[A] = ln[A]o - k*t

ln[A] = ln(1.1) - 3.609*10^-3*32

ln[A] = 9.531*10^-2 - 3.609*10^-3*32

ln[A] = -2.019*10^-2

[A] = e^(-2.019*10^-2)

[A] = 0.980 ug

Answer: 0.980 ug

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
At 8:00 A.M., a patient receives a 1.1-μg dose of I-131 to treat thyroid cancer. Part...
At 8:00 A.M., a patient receives a 1.1-μg dose of I-131 to treat thyroid cancer. Part A: If the nuclide has a half-life of 8.0 days, what mass of the nuclide remains in the patient at 4:00 P.M. the next day? (Assume no excretion of the nuclide from the body.) Express your answer using two significant figures. m =   μg  
The iodine isotope 131 53 I (half-life = 8 days, atomic mass = 131 u) is...
The iodine isotope 131 53 I (half-life = 8 days, atomic mass = 131 u) is used in hospitals for diagnosis of thyroid function. (1 u = 1.66 x 10-27 kg). If 682 μg (1 μg = 10-6 g) are ingested by a patient, determine the activity (a) Immediately (b) One hour later, when the thyroid is being tested (c) Six months later (assume the iodine is still in the patient’s body)
1.Iodine-131 is administered orally in the form of NaI(aq) as a treatment for thyroid cancer. The...
1.Iodine-131 is administered orally in the form of NaI(aq) as a treatment for thyroid cancer. The half-life of iodine-131 is 8.04 days. How much time is required for the activity of a sample of iodine-131 to fall to 18.8 percent of its original value? Answer in days: 2. Iodine-131 is administered orally in the form of NaI(aq) as a treatment for thyroid cancer. The half-life of iodine-131 is 8.04 days. If you begin with 46.7 mg of this isotope, what...
A patient ingests 140 mg of 131I (iodine-131), a beta emitter with a half-life of 8.0...
A patient ingests 140 mg of 131I (iodine-131), a beta emitter with a half-life of 8.0 days. Assuming that none of the 131I is eliminated from the person's body in the first 4.0 hours of treatment, what is the exposure (in Ci) during those 4.0 hours? Express your answer using two significant figures. exposure= _____ Ci