ACIDS-BASES II
1)Which are the correct pair of dissociation equilibrium reactions forHCO3-(aq)?
a)
HCO3-(aq) + H+(aq)H2CO3(aq)
HCO3-(aq) + OH-(aq)H2CO42-(aq)
b)
HCO3-(aq) + H2O (l)H3CO4-(aq)
HCO3-(aq) + H2O (l)CO32-(aq) + H3O+(aq)
c)
HCO3-(aq)OH-(aq) + CO2(g)
HCO3-(aq) + H2O (l)H2CO3(aq) + OH-(aq)
d)
HCO3-(aq)H+(aq) + CO32-(aq)
HCO3-(aq) + H2O (l)H2CO3(aq) + OH-(aq)
2)Which of the following is the most basic?
a)HClO4(aq)
b)HClO3(aq)
c)HClO2(aq)
d) HOCl (aq)
3)Which best describes a Brønsted-Lowry acid?
a) electron-pair donor
b) electron-pair acceptor
c) proton donor
d) proton acceptor
4)Which best describes a Brønsted-Lowry base?
a) electron-pair donor
b) electron-pair acceptor
c) proton donor
d) proton acceptor
5)Which of the following would be possible for both strongly acidic and strongly basic solutions?
a) solution has[ H+]of 1.0 x 10-7M
b) solution turns red litmus blue
c) solution is a good conductor of electricity
d) solution liberates hydrogen gas when reacted with zinc metal
6)Which of the following is NOT a Brønsted-Lowry acid-base reaction?
a)NH3+ H2ONH4++ OH-
b)NH3+ BF3NH3BF3
c)HSO4-+ H+H2SO4
d)H3O++ OH-2 H2O
7)Which of the following would be the strongest base?
a)S2-
b)HSO3-
c)HSO32-
d)HS-
8)The reaction:
HB (aq) + C-(aq)HC (aq) + B-(aq)+ energy
will favour formation of the products if:
a)B-is a stronger acid thanC-
b) HB is a stronger acid than HC
c) the bond in HB is stronger than the bond in HC
d) the temperature is increased
9)If you were to design a strong acid, which of the following characteristics would it have?
i) large amounts of electron drift towards the H atom
ii) a highly polar H-X bond
iii) the central atom has a high oxidation number
a) i) only
b) ii) only
c) iii) only
d) ii) and iii) only
e) all of the above
10)K values are not constant with respect to temperature. For example, as the temperature of water increases, the K value increases. At37oC, theKw= 2.4 x10-14. Given:
Kw= [ H+][ OH-],
pure water at37oChas a pH:
a) 7
b) greater than 7
c) less than 7
d) pH is invalid at such a temperature
11)What is the percent increase in[ H3O+]when the pH of blood drops from 7.4 to 7.3? ______
12)For a 1.0 M oxalic acid solution:
H2C2O4(aq)HC2O4-(aq) + H+(aq)
Ka= [ H+][ HC2O4-] / [H2C2O4]
Ka= 6.4 x 10-5at 25oC
At equilibrium, which of the species will be present in the greatest concentration?
i) H+
ii) HC2O4-
iii)H2C2O4
a) i) only
b) ii) only
c) iii) only
d) i) and ii) only
13)The pH of our blood is controlled by the bicarbonate buffer system:
CO2(g)CO2(aq)+ H2O(l)H2CO3(aq)H+(aq)+ HCO3-(aq)
Based only on the equilibria given here and the knowledge that CO2is released into the blood in the tissues and removed from the blood in the lungs, predict which area of the body has a higher pH:
a) tissues
b) lungs
14)What happens to the percent ionization when a solution of a weak acid is diluted?
The[ H3O ]at25oC, in a 0.00040 M solution of KOH (a strong electrolyte) is:
a)2.5 x 10-11
b)4.0 x 10-4
c)2.5 x 10-10
d)2.5 x 10-3
15)What is the percent ionization of a 0.15 M HF solution?Ka= 6.6 x 10-4
16)Imagine that you are titrating a known volume of dilute acetic acid with 0.1M NaOH in order to determine the concentration of acetic acid, using phenol red as your indicator. However, instead of adding only a few drops, you accidentally pour in the whole bottle of phenol red. Is this likely to be a problem?