Monoclinic needles (lamellar twinning on 001) from water, mp 357°. Sublimes 290-295°. Kb at 18°:
1.3 ´ 10-14; Ka 0.9 ´ 10-10.
this is what the merck index has stated...
I don't understand what "Monoclinic needles" are.. what Kb stands for and why its "1.3 ' 10-14" and what Ka is and why its "0.9 ' 10-10"
1.3 ´ 10-14; Ka 0.9 ´ 10-10.
this is what the merck index has stated...
I don't understand what "Monoclinic needles" are.. what Kb stands for and why its "1.3 ' 10-14" and what Ka is and why its "0.9 ' 10-10"
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Monoclinic refers to a crystal shape.
Imagine a cube.
It has 3 dimensions: a, b, and c.
It has 3 angles: α, β, and γ
In a cube, a=b=c, and α = β = γ = 90°
Monoclinic means that either 1 angle or all 3 angles are not 90°
Needle means that c is much larger than a or b.
Ka is a measure of how much a H+ ion dissociates from a molecule, say HA.
For the reaction HA → H+ + A-
Ka = [H+] x [A-] / [HA] where the square brackets mean molar concentration.
Since Ka ~ 1E-10 relatively little dissociates, (about 1 in 100,000 molecules.(1E-5)
Kb is a similar measure of how strongly a molecule attracts a H+ ion from water,
(or how much OH- it forms)
For the reaction B + H2O → BH+ + OH-
Kb = [BH+] x [OH-] / [B]
Since the Kb is ~1E-14, relatively little OH- is formed, (about 1 in 10million molecules (1E-7)
Imagine a cube.
It has 3 dimensions: a, b, and c.
It has 3 angles: α, β, and γ
In a cube, a=b=c, and α = β = γ = 90°
Monoclinic means that either 1 angle or all 3 angles are not 90°
Needle means that c is much larger than a or b.
Ka is a measure of how much a H+ ion dissociates from a molecule, say HA.
For the reaction HA → H+ + A-
Ka = [H+] x [A-] / [HA] where the square brackets mean molar concentration.
Since Ka ~ 1E-10 relatively little dissociates, (about 1 in 100,000 molecules.(1E-5)
Kb is a similar measure of how strongly a molecule attracts a H+ ion from water,
(or how much OH- it forms)
For the reaction B + H2O → BH+ + OH-
Kb = [BH+] x [OH-] / [B]
Since the Kb is ~1E-14, relatively little OH- is formed, (about 1 in 10million molecules (1E-7)