Acids                Quiz #5         pH calculations for Strong and Weak Acids

1.         The 1.0 M acidic solution with the highest pH is

A.        H2S

B         HNO2

C.        HNO3

D.        H3BO3

2.         At 25 oC, the equation representing the ionization of water is

A         H2O + H2O 2H2 + O2

B.        H2O + H2O H2O2    + H2

C.        H2O + H2O 4H+ + 2O2-

D.        H2O + H2O H3O+ +OH-

3.         The pH of a 0.3 M solution of NH3 is approximately

A.        14.0

B.        11.0

C.        6.0

D.        3.0

4.         The pH of an aqueous solution is 4.32. The [OH-] is

A.        6.4 x 10-1 M

B.        4.8 x 10-5 M

C.        2.1 x 10-10 M

D.        1.6 x 10-14 M

5.         The pH of an aqueous solution is 10.32. The [OH-] is

A.        5.0 x 10-12 M

B.        2.0 x 10-11 M

C.        4.8 x 10-11 M

D.        2.1 x 10-4 M

6.         The pH of a 0.025 M HClO4 solution is

A.        0.94

B.        1.60

C.        12.40

D.        13.06

7.         Consider the following equilibrium

H2O(l) H2O(l) H3O+(aq) + OH-(aq)

The equilibrium constant for this system is referred to as

A.        Kw

B.        Ka

C.        Kb

D.        Ksp

8.         The [H3O-] in a solution of pH 0.60 is

A.        4.0 x 10-14 M

B.        2.2 x 10-1 M

C.        2.5 x 10-1 M

D.        6.0 x 10-1 M

9.         A solution is prepared by adding 100 mL of 10 M of HCl to a 1 litre volumetric

flask and filling it to the mark with water. The pH of this solution is

A.        -1

B.        0

C.        1

D.        7

10.       The approximate pH of a 0.06 M solution of CH3COOH is

A.        1

B.        3

C.        11

D.        13

11.       The [OH-] is greater than the [H3O+] in

A.        HCl(aq)

B.        NH3(aq)

C.        H2O(aq)

D.        CH3COOH(aq)

12.       The pH of 0.15 M HCl is

A.        0.15

B.        0.71

C.        0.82

D.        13.18

13.       Which of the following equations correctly relates pH and [H3O+] ?

A.        pH= log [H3O+]

B.        pH= 14 -  [H3O+]

C.        pH= -log [H3O+]

D.        pH= pKw – [H3O+]

14.       The pH of 0.20 M HNO3 is

A.        0.20

B.        0.63

C.        0.70

D.        1.58

15.       The [OH-] in 0.050 M HNO3 at 25oC is

A.        5.0 x 10-16 M

B.        1.0 x 10-14 M

C.        2.0 x 10-13 M

D.        5.0 x 10-2 M

16.       What is the approximate pH of a 1.0 M solution of the salt NH4Cl?

A.        0.0

B.        5.0

C.        7.0

D.        10.0

17.       What is the approximate pH of a 1.0 M solution of the salt NH3?

A.        2.0

B.        5.0

C.        7.0

D.        10.0

18.       What is the approximate pH of a 1.0 M solution of the salt NaHCO3?

A.        2.0

B.        5.0

C.        7.0

D.        9.0

19.       What is the approximate pH of a 1.0 M solution of the salt AlCl3?

A.        0.0

B.        3.0

C.        7.0

D.        9.0

20.       What is the approximate pH of a 1.0 M solution of the salt NaHSO4?

A.        0.0

B.        3.0

C.        7.0

D.        9.0

21.       Which of the following is a definition of pH?

A.        pH  =  +Log[H3O+]

B.        pH  =  -Log[OH-]

C.        pH  =  -Log[H3O+]

D.        pH  =  pOH  +  pKw

22.       What is the mass of NaOH required to prepare 100.0 mL of NaOH(aq) that has a

pH = 13.62 ?

A.        0.38 g

B.        0.42 g

C.        1.67 g

D.        0.14 g

23.       What is the [KOH] in a KOH solution that has a pH =12.00?

A.        0.010 M

B.        0.56 M

C.        2.0 M

D.        2.0  x  10-12 M

24.       What is the [H3O+] in 0.70 M HCN ?

A.        0.70 M

B.        1.9  x  10-5 M

C.        1.0  x  10-6 M

D.        2.4  x  10-10 M

25.       What is the value of pKw for water at 25 0C ?

A.        10  x  10-14

B.        10  x  10-7

C.        7.00

D.        14.00

26.       What pH would most likely result when CO2 dissolves naturally in rainwater?

A.        3.5

B.        6.5

C.        7.2

D.        7.8

27.       What is the pOH of 0.05 M Ba(OH)2 ?

A.        1.0

B.        1.3

C.        12.7

D.        13.0

28.       What is the pH of 0.5 M Sr(OH)2 ?

A.        0.0

B.        0.3

C.        12.7

D.        14.0

29.       Which of the following statements is true for an acidic solution at 25 0C ?

A.        pH  >  7.0

B.        pOH  <  7.0

C.        [H3O+]  <  [OH-]

D.        [H3O+]  >  [OH-]

30.       What is the [OH-] in 0.025 M HCl ?

A.        2.5  x  10-16 M

B.        4.0  x 10-13 M

C.        2.5  x  10-2 M

D.        1.6 M