Posted by **cam** on Monday, April 11, 2011 at 7:07pm.

caffeine has a half-life of 4.6 hours in the human body.. How long would it take 125 milligrams tritium to decay to 22 milligrams?

- chemistry -
**DrBob222**, Monday, April 11, 2011 at 10:49pm
Pray tell what does caffeine have to do with tritium?

For tritium,

k = 0.693/t_{1/2}

You will need to look up the half-life of tritium unless that is the "caffeine" half-life.

Substitute k into the below equation.

ln(No/N) = kt

Nl = 125

N = 22

k = from above calculation.

t = time. Solve for this. Note that the unit for time and the unit for half-life must be the same.

## Answer this Question

## Related Questions

Pre Calc! - A drug is eliminated from the body through urine. Suppose that for a...

Pre Calc! - A drug is eliminated from the body through urine. Suppose that for a...

chemistry - If there are 80 milligrams of a radioactive element decays to 10 ...

math - 3. The half-life of a certain drug in the human body is 8 hours how long...

algebra - half lives - Half-life of tritium is 12.32 years. Write decay equation...

math - How do I set-up/solve this problem? Please help me. The half-life of the ...

calculus - How do I set-up/solve this problem? Please help me. The half-life of ...

Chemistry - A pure sample of tritium, 3H, was prepared and sealed in a container...

Calculus - Ba has a half-life of 283.2 hours. How long would it take for the 50 ...

Calculus - If 40 milligrams of strontium-90 radioactively decays to 12 ...