Answer:
The amount of drug left in his body at 7:00 pm is 315.7 mg.
Explanation:
First, we need to find the amount of drug in the body at 90 min by using the exponential decay equation:
Where:
λ: is the decay constant = 
: is the half-life of the drug = 3.5 h
N(t): is the quantity of the drug at time t
N₀: is the initial quantity
After 90 min and before he takes the other 200 mg pill, we have:
Now, at 7:00 pm we have:
Therefore, the amount of drug left in his body at 7:00 pm is 315.7 mg (from an initial amount of 400 mg).
I hope it helps you!
Answer: In the chemical formula for water, the subscript for hydrogen is 2. Notice that the 2 is smaller and written slightly below the H and O. It is called a subscript because it is written ("script") "below" ("sub") the preceding letter.
Explanation:
Answer:
Near the boiling point of the solvent
Explanation:
The process of recrystallization is hinged on the fact that the amount of solute that can be dissolved by a solvent increases with temperature. The process involves creation of a solution by dissolving a solute in a solvent at or near its boiling point. At the boiling point of the solvent, the solute has a greater solubility in the solvent; not much volume of the hot solvent is required to dissolve the solute.
Before the solution is later cooled, you can now filter out insoluble impurities from the hot solvent. The quantity of the original solute drops appreciably because impurities have been removed. At this lower temperature, the solution becomes saturated and the solute can no longer be held in solution hence it forms pure crystals of solute, which can be recovered.
Recrystallization must be carried out using the proper solvent. The solute must be relatively insoluble in the solvent at room temperature but more soluble in the solvent at elevated temperature.
Answer:
C5H5N is the base and C5H5NH+ is the conjugate acid
H2O is the acid and OH− is the conjugate base
Explanation:
<u>Hydrogen + is also called a proton</u>
C5H5N is the base because it receives the proton (H+) and C5H5NH+ is its conjugate acid
H2O is the acid because it gives up the proton and OH− is the conjugate base because it is capable of receiving the proton
Answer:
HNO3 is the acid and NO3- is the conjugate base
H2O is the base and H3O+ is the conjugate acid
Explanation
HNO3 is the acid and NO3− is its conjugate base, capable of receiving a proton
H2O is the base because it receives the proton and H3O+ is a conjugate acid capable of giving up the proton.
