Answer:
Explanation:
Caffeine is a weak base with pKb = 10.4
Kb = 10⁻¹⁰°⁴ = 3.98 x 10⁻¹¹
molecular weight of caffeine = 194.2
455 x 10⁻³ g / L = 455 x 10⁻³ / 194.2 moles / L
concentration of given solution a = 2.343 x 10⁻³ M
Let the caffeine be represented by B .
B + H₂O = BH + OH⁻
a - x x x
x² / ( a - x ) = Kb
x² / ( a - x ) = 3.98 x 10⁻¹¹
x is far less than a so a -x is almost equal to a
x² = 3.98 x 10⁻¹¹ x 2.343 x 10⁻³ = 9.32 x 10⁻¹⁴
x = 3.05 x 10⁻⁷
[ OH⁻ ] = 3.05 x 10⁻⁷
pOH = - log ( 3.05 x 10⁻⁷ )
= 7 - log 3.05
= 7 - 0.484 = 6.5
pH = 14 - 6.5 = 7.5
Answer:
It remains the same
Explanation:
The law of conservation of mass states that, during a chemical reaction, the total mass of the products must be equal to the total mass of the reactants.
The number of electrons, which are present in the nonbonding π molecular orbital of the allyl anion is "0".
Anions, cations, but also allylic radicals have always been frequently mentioned as reaction intermediates. Each one has three adjacent
-hybridized carbon centers, and they all rely on resonance for stability. Two resonance structures would be used to present each species, with the charge as well as unpaired electron scattered across both the 1,3 and 0 positions.
The Aufbau principle states that these orbitals would fill up based on the order of stability, therefore a typical pi bond, will have 2 electrons in the Pi orbital as well as zero in the Pi* orbital.
Therefore, the correct answer will be option (d)
To know more about allyl anion
brainly.com/question/14286167
#SPJ4
The Milky Way is a SBc barred spiral galaxy.
Answer:
Mitochondria is the powerhouse of the cell, but don't let this distract you from the fact that Mr. Krabs sold SpongeBob's soul for 62 cents