Unit 10: Intro to Acids and Bases, pKa

Question 1

approximate pKa of HCl

Answer 1

-7

Question 2

approximate pKa of Hydronium (H3O+)

Answer 2

-1.75

Question 3

approximate pKa of carboxylic acids (RCOOH)

Answer 3

4-5

Question 4

approximate pKa of Ammonium (NH4+)

Answer 4

9.24

Question 5

approximate pKa of Water (H2O)

Answer 5

15.7

Question 6

approximate pKa of alcohols (ROH)

Answer 6

16-18

Question 7

approximate pKa of alkynes

Answer 7

25

Question 8

approximate pKa of amines

Answer 8

38

Question 9

approximate pKa of alkenes

Answer 9

44

Question 10

approximate pKa of alkanes

Answer 10

50

Question 11

Bronsted-Lowry Acids and Bases: Acids are ___________, and bases are __________

Answer 11

proton donors
proton acceptors

Question 12

proton =

Answer 12

“H” atom

Question 13

An acid-base reaction is also called a _____________, because protons are moved from the acid to the base. Conjugate acid-base pairs are any pair of molecules that can be turned into one another by simply _______________

Answer 13

proton-transfer reaction
transferring one proton (usually H)

Question 14

pKa is the measure of the ________ of an acid.

Answer 14

relative strength

Question 15

The lower the pKa, the _______ the acid.

Answer 15

stronger

Question 16

Acid – proton =

Answer 16

Conjugate Base (CB)

Question 17

Base + proton =

Answer 17

Conjugate Acid (CA)

Question 18

Conjugate Base (CB) =

Answer 18

Acid – proton

Question 19

Conjugate Acid (CA) =

Answer 19

Base + proton

Question 20

Curved arrows coming from ________ indicate the formation of a new bond

Answer 20

a lone pair to a new atom

Question 21

Curved arrows coming from __________ indicate the breaking of that bond

Answer 21

a bond to one of the atoms in that bond

Question 22

H2O is in _______ of the acid, so its concentration essentially remains _______

Answer 22

large excess
constant

Question 23

The lower the pKa , the ______ the acid and the _______ the conjugate base

Answer 23

stronger
weaker

Question 24

The higher the pKa , the _______ the acid and the ________ the conjugate base

Answer 24

weaker
stronger

Question 25

Since pKa is the inverse log of Ka , pKa decreases as ______ increases

Answer 25

Ka

Question 26

Ka is a measure of…

Answer 26

acid dissociation in water

Question 27

Ka tells us about the bond strength between an ______ and ___________

Answer 27

acid
its acidic proton (H)

Question 28

Acids are protonated when the pH is _______ than the pKa

Answer 28

lower

Question 29

If the pH is higher the pKa of the acid, then the acid will be ___________

Answer 29

deprotonated

Question 30

pKa is ________ related to the acid strength

Answer 30

inversely

Question 31

The ______ the pKa, the stronger the acid

Answer 31

lower

Question 32

The weaker the acid, the _________ the conjugate base

Answer 32

stronger

Question 33

Acids are deprotonated when the pH is _______ than the pKa

Answer 33

higher

Question 34

If the pH is below the pKa of the acid, then the acid will be ________

Answer 34

protonated