We are given the base dissociation constant, Kb, for Pyridine (C5H5N) which is 1.4x10^-9. The acid dissociation constant, Ka for the Pyridium ion or the conjugate acid of Pyridine is to be determined. We know from our chemistry classes that:
Kw = Kb * Ka
where Kw is always equal to 1x10^-14
so, to solve for Ka of Pyridium ion, substitute Kb to the equation together with Kw and solve for Ka:
1x10^-14 = 1.4x10^-9 * Ka
solve for Ka
Ka = 7.14x10^-6
Therefore, the acid dissociation constant of Pyridinium ion is 7.14x10^-6.
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Answer:
The quantity of ascorbic acid found in sweet lime of 49.6 mg does not meet the daily requirement.
Explanation:
To determine the mass of ascorbic acid knowing the number of moles we use the following formula:
number of moles = mass / molecular weight
mass = number of moles × molecular weight
mass of ascorbic acid = 2.82 × 10⁻⁴ × 176
mass of ascorbic acid = 496 × 10⁻⁴ g = 0.0496 g = 49.6 mg
daily requirement of ascorbic acid = 70 - 90 mg
The quantity of ascorbic acid found in sweet lime of 49.6 mg does not meet the daily requirement.
Answer:
it has six significant figures
