2H2 (g) + O2 (g) -->2H2 O(g)
mole ratio of H2:O2=2:1
7.25/2=3.625
<h3>
Answer:</h3>
P₂ = 0.67 atm
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality<u>
</u>
<u>Chemistry</u>
<u>Gas Laws</u>
Boyle's Law: P₁V₁ = P₂V₂
- P₁ is pressure 1
- V₁ is volume 1
- P₂ is pressure 2
- V₂ is volume 2
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
[Given] P₁ = 2.02 atm
[Given] V₁ = 4.0 L
[Given] V₂ = 12.0 L
[Solve] P₂
<u>Step 2: Solve</u>
- Substitute in variables [Boyle's Law]: (2.02 atm)(4.0 L) = P₂(12.0 L)
- [Pressure] Multiply: 8.08 atm · L = P₂(12.0 L)
- [Pressure] [Division Property of Equality] Isolate unknown: 0.673333 atm = P₂
- [Pressure] Rewrite: P₂ = 0.673333 atm
<u>Step 3: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs as our smallest.</em>
0.673333 atm ≈ 0.67 atm
Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay.
We have the following equation representing the half-life decay:

A is the resulting amount after t time
Ao is the initial amount = 50 mg
t= Elapsed time
t half is the half-life of the substance = 14.3 days
We replace the know values into the equation to have an exponential decay function for a 50mg sample

That would be the answer for a)
To know the P-32 remaining after 84 days we have to replace this value in the equation:

So, after 84 days the P-32 remaining will be 0.85 mg
<span>pharmacokinetics
This question is simply a matter of knowing the definition of terms being used in your class. So let's look at the 4 options and see what makes sense.
spectrometry
* This is the determination of elements based upon the light spectrum associated with the elements. It can be either an emission spectrum you get by energizing the substance under test, or an absorption spectrum to see what wavelengths the substance absorbs. But in either case, this doesn't make sense in the statement, so it's a wrong answer.
LD50
* This terms means "Lethal Dose 50%" which is the amount of the substance needed such that half of the creatures that receive that dose die. In the context of the statement, this doesn't make sense, so it's a wrong answer.
pharmacokinetics
* This is the study of how drugs move through the body and are metabolized. This sounds like something that makes sense for the statement in the question, so it's most likely the correct answer. Let's see what the next choice is.
chromatography
* This is a laboratory method of separating substances using differential rates of diffusion. This doesn't make sense given the statement in the question, so it's a wrong choice.
So of the 4 available choices, 3 of them do not make sense given the statement in question and the only one that does make sense is "pharmacokinetics"</span>