A 1.00 mL sample of red blood cells containing chromium-51 as a tracer was injected into a patient. After several hours, a 5.00 mL sample of blood was drawn and its activity compared to the activity of the injected tracer sample. If the collected sample activity was 0.10% of the original tracer, calculate the total blood volume of the patient (see the Chemistry in Action 'Medical Uses of Radioactivity,' p. 338).
Ch.11 Nuclear Chemistry
McMurry8th EditionFundamentals of General, Organic, and Biological ChemistryISBN: 9780134015187Not the one you use?Change textbook
Chapter 11, Problem 13
A solution of selenium-75, a radioisotope used in the diagnosis of pancreatic disease, is found just prior to administration to have an activity of 44 μCi/mL. If 3.98 mL were delivered intravenously to the patient, what dose of Se-75 (in μCi) did the patient receive?
Verified step by step guidance1
Step 1: Understand the problem. The activity of the selenium-75 solution is given as 44 μCi/mL, and the volume administered to the patient is 3.98 mL. The goal is to calculate the total dose of selenium-75 (in μCi) received by the patient.
Step 2: Recall the formula for calculating the total dose. The total dose can be calculated by multiplying the activity of the solution by the volume administered:
Step 3: Substitute the given values into the formula. The activity is 44 μCi/mL, and the volume is 3.98 mL. The equation becomes:
Step 4: Perform the multiplication to calculate the total dose. Multiply the activity (44 μCi/mL) by the volume (3.98 mL) to find the dose in μCi.
Step 5: Ensure the units are consistent. Since the activity is in μCi/mL and the volume is in mL, the resulting dose will be in μCi, which is the desired unit for the answer.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Radioactivity
Radioactivity is the process by which unstable atomic nuclei lose energy by emitting radiation. This decay can be measured in terms of activity, typically expressed in curies (Ci) or microcuries (μCi). Understanding radioactivity is essential for calculating the amount of a radioactive substance administered in medical applications, such as in the case of selenium-75.
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Dosage Calculation
Dosage calculation involves determining the total amount of a substance administered to a patient based on its concentration and the volume delivered. In this scenario, the activity of selenium-75 is given in μCi/mL, and by multiplying this concentration by the volume administered (in mL), one can find the total dose received by the patient in microcuries.
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Intravenous Administration
Intravenous (IV) administration is a method of delivering substances directly into the bloodstream through a vein. This route allows for rapid distribution of medications or radioisotopes, making it crucial in medical diagnostics and treatments. Understanding IV administration is important for accurately assessing the dosage and effects of substances like selenium-75 in patients.
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What is wrong with the following decay curve? Explain.
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