CHEM UN1604 Midterm: C1604_2018_PR_EXAM1_KEY

11) The name given to an aqueous solution of HNO₃ is

A) nitric acid

B) nitrous acid

C) hydrogen nitrate

D) hydronitrogen acid

E) hyponitric acid

12) The conjugate acid of HSO₄^- is

A) SO₄^2-

B) HSO₄

C) H₂SO₄.

D) H₂SO₄^-

E) HSO₃^-

13) What is the [OH^-] in a solution that has a [H₃O⁺] = 1 x 10^-6 M?

A)1 x 10^-2 M

B) 1 x 10^-6 M

C)1 x 10^-8 M

D) 1 x 10^-10 M

E) 1 x 10^-12 M

14) A solution which has [OH^-] = 4.6x 10^-6 M is

A) acidic

B) basic

C) neutral

15) What is the pH of a solution with [H₃O⁺] = 1 x 10^-9 M

A) 1.0 x 10^-5 M

B)-9.0

C) 5.0

D) -5.0

E) 9.0

16) Which of the following could be a buffer?

A) NaF

B) HF+NaF

C) HF+H₂O

D) NaF+H₂O

E) NaCl+HF

1)What is the hydroxide ion concentration of a solution with a pH of 4?
a) 10^-10
b) 10^-8
c) 10^-6
d) 10^-4
e) 10^-2

2) which of the following would be the strongest acid?
a) HXO
b) HXO2
c) HXO3
d) HXO4

3) why is HF a weak acid and HCL is a strong acid?
a) because HF has a stronger Bond than HCL
b) because HF is more polar than HCL
c) because HF of has hydrogen bonding
d) the statement is untrue, they both are strong acids

4) what is the pH of 0.1 M HNO3?
a) 0
b) 1
c) 2
d) 3
e) 13

5) what is the pH of 0.25 M KOH?
a) 13.8
b) 13.4
c) 12.8
d) 12.4
e) 10.5

6) a 0.30 M solution of a weak base has a pH of 11.12 what is the Kb for the base?
a 4.3×10^-6
b 5.4×10^-2
c 1.3×10^-5
d 5.9×10^-6

7) 10.0 mL of 0.50 M NaOH is added to 30.0 mL of 0.20M HCl. what is the pH of the mixture?
a 0.25
b 1.2
c 1.5
d 1.6

8) A NaOH solution has a pH of 12, what is it's concentration?
a 0.1
b 0.2
c 0.01
d 0.02

12 and 13 the diprotic acid H2A has a Ka1= 10^-5 and a Ka2= 10^-9. you can make up a 0.10M solution of H2A

12) what is the pH?
a 3
b 5
c 6
d 9

13) what is the concentration of the ion A^2-
a 10^-3
b 10^-5
c 10^-6
d 10^-9

14) which of the following salts has a ph of 7?
a NaBrO
b NaClO2
c KNO3
d (CH3)2NH2I

15) how many of the following salts are basic?
NaC2H3O2
KOH
BaSO3
KNO2
a 0
b 1
c 2
d 3
e 4