Ka, Kb, pKa and pKb

calculate the Ka of a solution with a pKb of 3.38

• 3.38x10^-11

• 6.76x10^-11

• 2.40x10^-11

• 2.39x10^-11

calculate the pKb of solution with a pKa of 6.9

• 7.1

• 6.5

• 14

• 9.6

Calculate the Kb of a solution that has a pKb of 4.2

• 0.62

• 6.3x10^-5

• 9.8

• 4.2

The magnitude of Kw indicates that ______________.

• water autoionizes very slowly

• water autoionizes very quickly

• water autoionizes only to a very small extent

• the autoionization of water is exothermic

How would you calculate K_b for the formate ion (HCOO^–), given that the K_a for formic acid (HCOOH) is 1.8 × 10^–4? (K_w=1.0 × 10^–14)

• K_b = K_a × K_w

• K_b = K_w / K_a

• K_b = K_a / K_w

• K_b = K_w + K_a

In which of the following aqueous solutions does the weak acid exhibit the highest percentge of ionization?

• .01 M HC₂H₃O₂ . (K_a 1.8 x 10 ^-5)

• .01 M HNO₂ . ( Ka =4.5 x 10 ^-4)

• .01 M HClO . (Ka= 3.0 x 10 ^-8)

• .01 M HF (Ka= 6.8 x 10 ^-4)

HA is a weak acid. Which equilibrium corresponds to the equilibrium constant K_b for A^-?

• HA _(aq) + H₂O _(l) <---> H₂A^+ _(aq) + OH^-_(aq)

• A^- _(aq) + H₃O⁺ _(aq) <---> HA _(aq) + H_2O _(l)

• HA _(aq) + OH^- _(aq) <---> H₂O _(l) + H^+ _(aq)

• A^- _(aq) + H₂O _(l) <---> HA _(aq) + OH^- _(aq)

• A^- _(aq) + OH^- _(aq) <---> HOA^2- _(aq)

A^- is a weak base. Which equilibrium corresponds to the equilibrium constant K_a for HA?

• HA _(aq) + H₂O _(l) <---> H₂A⁺ _(aq) + OH^- _(aq)

• A^- _(aq) + H₃O⁺ _(aq) <---> HA _(aq) + H_2O _(l)

• HA _(aq) + H₂O _(l) <---> H₃O⁺ _(aq) + A^- _(aq)

• A^- _(aq) + H₂O _(l) <---> HA _(aq) + OH^- _(aq)

• A^- _(aq) + OH^- _(aq) <---> HOA^2- _(aq)

Tags

NGSS.HS-PS1-6

Using the data in the table, which of the conjugate bases below is the weakest base?

• OAc^-

• C₇H₅O₂^-

• NO₂^-

• F^-

• OAc^- and C₇H₅O₂^-

Using the data in the table, which of the conjugate acids below is the weakest acid?

• HClO

• HCO₃^-

• H₂S

• NH₃CH₃⁺

• H₂S and HClO