CHEMISTRY WKST KEY: ACIDS / BASES REVIEW
1)
a) endpoint → the point in a titration when the indicator changes color to signal the end of the titration
b) equivalence point → the point in a titration when the [H+] = [OHˉ]
2)
Arrhenius theory
Bronsted-Lowry theory
acid
increases H+ concentration in H2O
proton (H+) donor
base
increases OHˉ concentration in H2O
proton (H+) accepton
3)
A strong acid or base will completely dissociate into its ions when dissolved. A weak acid or base only partially
dissociates.
4)
a)
b)
c)
d)
strong acid
weak acid
strong base
weak acid
e)
f)
g)
h)
strong base
strong acid
weak base
weak base
5)
a)
N2H4 + H2O ⇄ N2H5+ + OHˉ
acids
H2O
N2H5+
b)
H2O + HCO3ˉ ⇄ CO32ˉ + H3O+
HCO3ˉ
H3O+
CO32ˉ
H2O
c)
HOCl + C6H5NH2 ⇄ OCl− + C6H5NH3+
HOCl
C6H5NH3+
OClˉ
C6H5NH2
d)
Cu(H2O)3(OH)+ + Al(H2O)63+ ⇄ Cu(H2O)42+ + Al(H2O)5(OH)2+
Cu(H2O)42+
Al(H2O)63+
Cu(H2O)3(OH)+
Al(H2O)5(OH)2+
6)
a) CNˉ
b) NH4+
c) HNO3
d) N2H5+
7)
a)
b)
c)
d)
e) acid
f) base
g) base
8)
a) HCl + KOH → H2O(l) + KCl
acid
base
acid
base
b) H2SO4 + 2NH4OH → 2H2O(l) + (NH4)2SO4
9)
10)
H+ + OH− → H2O(l)
a) pH = 2
b) pH = 10
c) pOH = 12
bases
OHˉ
N2H4
11)
[H+] = 1.00 x 10ˉ7 M
[OH-] = 1.00 x 10ˉ7 M
12)
a) pH = −log(3.25 x 10−4 M) = 3.488
pH = pOH = 7.00
b) pOH = −log(4.00 x 10−5 M) = 4.380
pH = 14 – pOH = 14 – 4.380 = 9.620
c) pH = 14 – pOH = 14 – 4.94 = 9.06
13)
a) pH = −log(9.05 x 10−6 M) = 5.043
pOH = 14 – pH = 14 – 5.043 = 8.957
b) pOH = −log(0.0446 M) = 1.351
c) pOH = 14 – pH = 14 – 12.20 = 1.80
14)
[HCl] = [H+]
[H+] = 10ˉpH = 10ˉ2.84 = 0.0014 M
15)
14 = pH + pOH

pOH = 14 – 5.85 = 8.15
[OHˉ] = 10ˉpH = 10ˉ8.15 = 7.08 x 10ˉ9 M
16)
a) HBr → H+ + Br1−
b) HClO3 → H+ + ClO3−
c) H2CrO4 ⇄ H+ + HCrO4−
HCrO4− ⇄ H+ + CrO42−
d) RbOH → Rb+ + OH−
e) Ba(OH)2 → Ba2+ + 2OH−
f)
NH4OH ⇄ NH4+ + OH−
17)
HNO3
H2SO4
HCl
NH4OH
H3PO4
HC2H3O2
18)
NAME
nitric acid
sulfuric acid
hydrochloric acid
ammonium hydroxide
phosphoric acid
acetic acid
COLOR
red
yellow
blue
green
white
brown
NaVa = NbVb
Va =
Nb Vb
(0.250 N)(250.0 mL)
=
= 125 mL
Na
0.500 N
19)
NaVa = NbVb
N𝑏 =
20)
N𝑎 Va
(0.183 N)(32.20 mL)
=
= 0.236 N
Vb
25.00 mL
a) neutral
b) basic
c) acidic
d) acidic
e) basic
f) basic
21)
x
x
22)
You want an indicator that has a pH range for its color change that falls on the vertical portion of the pH curve.
That way, with one drop, you hit the equivalence point and the endpoint.