is it true?

Question

Bigger pka = stronger acid? i.e. if there were two acids with one having pka of 3.25 and the other one 1.8, the first one would be stronger?

Answer 1

No, false. Lower pKa = stronger acid. Negative pKa's are even stronger acids.

Answer 2

smaller pKa stronger acid
pKa -5 stronger acid than pKa 5

Answer 3

In chemistry and biochemistry, the acid dissociation constant, the acidity constant, or the acid-ionization constant (Ka) is a specific type of equilibrium constant that indicates the extent of dissociation of hydrogen ions from an acid. The equilibrium is that of a proton transfer from an acid, HA, to water, H2O. The term for the concentration of water, [H2O], is omitted from the general equilibrium constant expression.

HA(aq) + H2O(l) ⇌ H3O+(aq) + A–(aq)

K_a = \frac{[\mbox{H}_3\mbox{O}^+][\mbox{A}^- ]} {[\mbox{HA}]}

The equilibrium is often written in terms of "H+(aq)", which reflects the Bronsted-Lowry Theory of acids.

HA(aq) ⇌ H+(aq) + A–(aq)

Because this constant differs for each acid and varies over many degrees of magnitude, the acidity constant is often represented by the additive inverse of its common logarithm, represented by the symbol pKa (using the same mathematical relationship as [H+] is to pH).

pKa = −log10 Ka

In general, a larger value of Ka (or a smaller value of pKa) indicates a stronger acid, since the extent of dissociation is larger at the same concentration.

Using the acid dissociation constants, the concentration of acid, its conjugate base, protons and hydroxide can be easily determined. If an acid is partly neutralized, the Ka can also be used to find the pH of the resulting buffer. This same information is summarized in the Henderson-Hasselbalch equation.

then it's completely false.....

best answer?

Answer 4

pKa is similar in its derivation to pH.

If an acid completely dissociates its dissociation constant, (Ka, the dissociation constant of the acid), is 1.

pKa is defined as being -log10 Ka

Therefore a lower Ka means a higher pKa.

The higher a pKa value the lower dissociation of the acid.

The scale is useful for comparing very poorly dissociated compounds such as ethyne.

Answer 5

Completely False

Answer 6

Nope, just the opposite.

The Ka equation for generic acid HX:

HX =====> H+ + X-

is Ka = [H+] [X-]/[HX], and

pKa = -log(base 10)[Ka]

so for your examples:

pKa = 3.25, Ka = 5.62E-4

pKa = 1.8, Ka = 1.58E-2

Answer 7

no but i'm still haveing trips so stay away from that stuff

Answer 8

is that microdot or blotter ?

Answer 9

no its not true