To calculate the pKa of the weak acid, we use the Henderson-Hasselbalch equation. It is expressed as pH = pKa - log [HA]/[A-]. This equation takes into account the concentration of the substance that does not dissociates into ions since it is a weak acid. We caculate as follows:
pH = pKa - log [HA]/[A-]
9 = pKa - log 1/100
pKa = 7
<span>A. Exact ecological footprints are often difficult to calculate, but estimates can be useful in comparing populations.
</span>Which of the following could be said about ecological footprints? <u /> <u>Exact ecological footprints are often difficult to calculate, but estimates can be useful in comparing populations.</u><u />
NOT:
b. Ecological footprints can't be used to determine carrying capacity.
C. Ecological footprints don't take into account resources needed to absorb and manage wastes.
<span>D. The average ecological footprints for various countries are nearly identical.</span>
Answer/Explanation:
Chlorine and Fluorine are in the Halogen family. The elements in the Halogen family are:
Fluorine (F)
Chlorine (Cl)
Bromine (Br)
Iodine (I)
Astatine (At)
Tennessine (Ts)
Hydrogen (H) is a nonmetal
Oxygen (O) is a nonmetal
Lithium (Li) is an alkaline metal.
Answer:
5.41 g
Explanation:
Considering:
Or,
Given :
For tetraphenyl phosphonium chloride :
Molarity = 33.0 mM = 0.033 M (As, 1 mM = 0.001 M)
Volume = 0.45 L
Thus, moles of tetraphenyl phosphonium chloride :
Moles of TPPCl = 0.01485 moles
Molar mass of TPPCl = 342.39 g/mol
The formula for the calculation of moles is shown below:
Thus,
Mass of TPPCl = 5.0845 g
Also,
TPPCl is 94.0 % pure.
It means that 94.0 g is present in 100 g of powder
5.0845 g is present in 5.41 g of the powder.
<u>Answer - 5.41 g</u>
