This problem is providing the basic dissociation constant of ibuprofen (IB) as 5.20, its pH as 8.20 and is requiring the equilibrium concentration of the aforementioned drug by giving the chemical equation at equilibrium it takes place. The obtained result turned out to be D) 4.0 × 10−7 M, according to the following work:

First of all, we set up an equilibrium expression for the given chemical equation at equilibrium, in which water is omitted for it is liquid and just aqueous species are allowed to be included:

$Kb=\frac{[IBH^+][OH^-]}{[IB]}$

Next, we calculate the concentration of hydroxide ions and the Kb due to the fact that both the pH and pKb were given:

$pOH=14-8.20=5.80$

$[OH^-]=10^{-5.8}=1.585x10^{-6}M$

$Kb=10^{-5.20}=6.31x10^{-6}$

Then, since the concentration of these ions equal that of the conjugated acid of the ibuprofen (IBH⁺), we can plug in these and the Kb to obtain:

$6.31x10^{-6}=\frac{(1.585x10^{-6})(1.585x10^{-6})}{[IB]}$

Finally, we solve for the equilibrium concentration of ibuprofen:

$[IB]=\frac{(1.585x10^{-6})(1.585x10^{-6})}{6.31x10^{-6}}=4.0x10^{-7}$

Learn more:

(Weak base equilibrium calculation) brainly.com/question/9426156

4 0

2 years ago

Which of the following best describes magnetic fields

BigorU [14]

Well the multiple choices for this question would be helpful, but from my own knowledge I would say:

Magnetic fields have north and south magnetic poles.

Magnetic fields have various characteristics which includes; they originate from the north poles and flow towards the south poles, they are exhibited in the form of magnetic field lines. Magnetic fields lines never cross one another,they all have the same strength and seek the path of least resistance between opposite magnetic poles etc.

3 0

2 years ago

Which component of the atom has the least mass HELLLP

Stolb23 [73]

From a Chemistry perspective it is the electron at 1/1800th the mass of a proton or neutron.

5 0

2 years ago

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