According to the Arrhenius concept, an acid is a substance that __________.
A) is capable of donating one or more H+
B) causes an increase in the concentration of H+ in aqueous solutions
C) can accept a pair of electrons to form a coordinate covalent bond
D) reacts with the solvent to form the cation formed by autoionization of that solvent
E) tastes bitter
A BrØnsted-Lowry base is defined as a substance that __________.
A) increases [H+] when placed in H2O
B) decreases [H+] when placed in H2O
C) increases [OH-] when placed in H2O
D) acts as a proton acceptor
E) acts as a proton donor
A BrØnsted-Lowry acid is defined as a substance that __________.
A) increases Ka when placed in H2O
Which one of the following is a BrØnsted -Lowry acid?
A) (CH3)^3NH+
B) CH3COOH
C) HF
D) HNO2
E) all of the above
A substance that is capable of acting as both an acid and as a base is __________.
A) autosomal
B) conjugated
C) amphoteric
D) saturated
E) miscible
6) Which one of the following is a BrØnsted -Lowry base?
A) (CH3)3N
E) none of the above
The molar concentration of hydronium ion in pure water at 25°C is __________.
A) 0.00
B) 1.0 × 10-7
C) 1.0 × 10-14
D) 1.00
E) 7.00
The magnitude of Kw indicates that __________.
A) water autoionizes very slowly
B) water autoionizes very quickly
C) water autoionizes only to a very small extent
D) the autoionization of water is exothermic
In basic solution, __________.
A) [H3O+] = [OH-]
B) [H3O+] > [OH-]
C) [H3O+] < [OH-]
D) [H3O+] = 0 M
E) [OH-] > 7.00
Which solution below has the highest concentration of hydroxide ions?
A) pH = 3.21
B) pH = 12.6
C) pH = 7.93
D) pH = 9.82
E) pH = 7.00
Which solution below has the highest concentration of hydronium ions?
Which one of the following statements regarding Kw is false?
A) pKw is 14.00 at 25°C
B) The value of Kw is always 1.0 × 10-14.
C) Kw changes with temperature.
D) The value of Kw shows that water is a weak acid.
E) Kw is known as the ion product of water.
The hydride ion, H-, is a stronger base than the hydroxide ion, OH-. The product(s) of the reaction of hydride ion with water is/ are __________.
A) H3O+ (aq)
B) OH- (aq) + H2 (g)
C) OH- (aq) + 2H+ (aq)
D) no reaction occurs
E) H2O2 (aq)
An aqueous solution contains 0.10 M NaOH. The solution is __________.
A) very dilute
B) highly colored
C) basic
D) neutral
E) acidic
Nitric acid is a strong acid. This means that __________.
A) aqueous solutions of HNO3 contain equal concentrations of H+(aq) and OH-(aq)
B) HNO3 does not dissociate at all when it is dissolved in water
C) HNO3 dissociates completely to H+(aq) and NO3-(aq) when it dissolves in water
D) HNO3 produces a gaseous product when it is neutralized
E) HNO3 cannot be neutralized by a weak base
Of the following acids, __________ is a strong acid.
A) HNO2
B) H2CO3
C) HBrO3
D) HClO
E) HF
Of the following acids, __________ is not a strong acid.
B) H2SO4
C) HNO3
D) HClO4
E) HCl
Which one of the following is the weakest acid?
A) HF (Ka = 6.8 × 10-4)
B) HClO (Ka = 3.0 × 10-8)
C) HNO2 (Ka = 4.5 × 10-4)
D) HCN (Ka = 4.9 × 10-10)
E) Acetic acid (Ka = 1.8 × 10-5)
The Ka of hypochlorous acid (HClO) is 3.0 × 10-8 at 25.0°C. What is the % ionization of hypochlorous acid in a 0.015 M aqueous solution of HClO at 25.0°C?
A) 4.5 × 10-8
B) 14
C) 2.1 × 10-5
D) 0.14
E) 1.4 × 10-3
In which of the following aqueous solutions does the weak acid exhibit the highest percentage ionization?
A) 0.01 M HC2H3O2 (Ka = 1.8 × 10-5)
B) 0.01 M HNO2 (Ka = 4.5 × 10-4)
C) 0.01 M HF (Ka = 6.8 × 10-4)
D) 0.01 M HClO (Ka = 3.0 × 10-8)
E) These will all exhibit the same percentage ionization.
In which of the following aqueous solutions does the weak acid exhibit the lowest percentage ionization?
HA is a weak acid. Which equilibrium corresponds to the equilibrium constant Kb for A-?
A) HA (aq) + H2O (l) --> H2A+ (aq) + OH- (aq)
B) A- (aq) + H3O+ (aq) --> HA (aq) + H2O (l)
C) HA (aq) + OH- (aq) --> H2O (l) + H+ (aq)
D) A- (aq) + H2O (l) --> HA (aq) + OH- (aq)
E) A- (aq) + OH- (aq) --> HOA2- (aq)
Using the data in the table, which of the conjugate acids below is the weakest acid?
A) HClO
B) HCO3-
C) H2S
D) NH3CH3+
E) H2S and HClO
A 0.0035 M aqueous solution of a particular compound has pH = 2.46. The compound is __________.
A) a weak base
B) a weak acid
C) a strong acid
D) a strong base
E) a salt
Which of the following aqueous solutions has the lowest [OH-]?
A) a solution with a pH of 3.0
B) a 1 × 10-4 M solution of HNO3
C) a solution with a pOH of 12.0
D) pure water
E) a 1 × 10-3 M solution of NH4Cl
Which of the following aqueous solutions has the highest [OH-]?
Of the following substances, an aqueous solution of __________ will form basic solutions.
NH4Cl Cu(NO3)2 K2CO3 NaF
A) NH4Cl, Cu(NO3)2
B) K2CO3, NH4Cl
C) NaF only
D) NaF, K2CO3
E) NH4Cl only
A 0.1 M aqueous solution of __________ will have a pH of 7.0 at 25.0°C.
NaOCl KCl NH4Cl Ca(OAc)2
A) NaOCl
B) KCl
C) NH4Cl
D) Ca(OAc)2
E) KCl and NH4Cl
Of the compounds below, a 0.1 M aqueous solution of __________ will have the highest pH.
A) KCN, Ka of HCN = 4.0 × 10-10
B) NH4NO3, Kb of NH3 = 1.8 × 10-5
C) NaOAc, Ka of HOAc = 1.8 × 10-5
D) NaClO, Ka of HClO = 3.2 × 10-8
E) NaHS, Kb of HS- = 1.8 × 10-7
A 0.1 M solution of __________ has a pH of 7.0.
A) Na2S
B) KF
C) NaNO3
D) NH4Cl
E) NaF
52) An aqueous solution of __________ will produce a basic solution.
A) NH4ClO4
B) KBr
C) NaCl
D) NaHSO4
E) Na2SO3
Of the following, which is the strongest acid?
A) HIO
B) HIO4
C) HIO2
D) HIO3
E) The acid strength of all of the above is the same.
Of the following, which is the weakest acid?
Which of the following acids will be the strongest?
A) H2SO4
B) HSO4-
C) H2SO3
D) H2SeO4
E) HSO3-
In the gas phase reaction below, NH3 is acting as a(n) __________ base but not as a(n) __________ base.
A) Arrhenius, BrØnsted-Lowry
B) BrØnsted-Lowry, Lewis
C) Lewis, Arrhenius
D) Lewis, BrØnsted-Lowry
E) Arrhenius, Lewis
What is the conjugate acid of NH3?
A) NH3
B) NH2+
C) NH3+
D) NH4+
E) NH4OH
What is the conjugate acid of CO3-2?
A) CO2-2
B) HCO2-2
C) H2CO3
D) HCO3-
The conjugate base of HSO4- is __________.
A) OH-
C) SO42-
D) HSO4+
E) H3SO4+
The conjugate base of H2PO4- is __________.
A) PO4-3
B) H2PO4
C) H3PO4
D) HPO4-2
The conjugate acid of HSO4- is __________.
A) SO42-
C) HSO4+
D) H+
E) HSO3+
What is the conjugate base of OH-?
A) O2
B) O-
C) H2O
D) O2-
E) H3O+
What is the pOH of an aqueous solution at 25.0 °C that contains 3.98 × 10-9 M hydronium ion?
A) 8.400
B) 5.600
C) 9.000
D) 3.980
E) 7.000
What is the pH of an aqueous solution at 25.0 °C that contains 3.98 × 10-9 M hydroxide ion?
A) 8.40
B) 5.60
C) 9.00
D) 3.98
What is the pOH of an aqueous solution at 25.0 °C that contains 3.98 × 10-9 M hydroxide ion?
Calculate the concentration (in M) of hydronium ions in a solution at 25.0°C with a pOH of 4.223.
A) 5.98 × 10-5
B) 1.67 × 10-10
C) 1.67 × 104
D) 5.99 × 10-19
E) 1.00 × 10-7
An aqueous solution contains 0.100 M NaOH at 25.0°C. The pH of the solution is __________.
A) 0.100
B) 1.00
C) 13.00
D) 7.00
E) -1.00
An aqueous solution contains 0.150 M HCl at 25.0°C. The pH of the solution is __________.
A) 0.150
E) 0.82
HZ is a weak acid. An aqueous solution of HZ is prepared by dissolving 0.020 mol of HZ in sufficient water to yield 1.0 L of solution. The pH of the solution was 4.93 at 25.0°C. The Ka of HZ is
A) 1.2 × 10-5
B) 6.9 × 10-9
C) 1.4 × 10-10
D) 9.9 × 10-2
E) 2.8 × 10-12
The pH of a 0.60 M aqueous solution of formic acid, HCHO2, at 25.0°C is 1.98. What is the value of Ka for formic acid?
A) 2.0 × 10-5
B) 1.8 × 10-4
C) 6.0 × 10-5
D) 3.5 × 10-4
A 0.15 M aqueous solution of the weak acid HA at 25.0°C has a pH of 5.35. The value of Ka for HA is __________.
A) 3.0 × 10-5
B) 1.8 × 10-5
C) 7.1 × 10-9
D) 1.3 × 10-10
E) 3.3 × 104
The Ka of hypochlorous acid (HClO) is 3.00 × 10-8. What is the pH at 25.0°C of an aqueous solution that is 0.0200 M in HClO?
A) +2.45
B) -2.45
C) -9.22
D) +9.22
E) +4.61
The acid-dissociation constants of sulfurous acid (H2SO3) are Kal = 1.7 × 10-2 and Ka2 = 6.4 × 10-8 at 25.0°C. Calculate the pH of a 0.163 M aqueous solution of sulfurous acid.
A) 4.53
B) 1.28
C) 1.86
D) 6.21
E) 1.93
The acid-dissociation constants of phosphoric acid (H2PO3) are Kal = 7.5 × 10-3, Ka2 = 6.2 × 10-8, and Ka3 = 4.2 × 10-13 at 25.0°C. What is the pH of a 2.5 M aqueous solution of phosphoric acid?
A) 1.82
B) 0.40
C) 2.51
D) 0.86
E) 0.13
The pH of a 0.55 M aqueous solution ammonia, NH3, at 25.0°C is 11.50. What is the value of Kb for NH3?
A) 2.0 × 10-9
B) 1.1 × 10-9
D) 1.8 × 10-5
The pH of a 0.30 M solution of a weak acid is 2.67. What is the Ka for this acid?
A) 2.1 × 10-4
B) 4.4 × 10-4
C) 1.5 × 10-4
D) 6.6 × 10-4
Z- is a weak base. An aqueous solution of NaZ is prepared by dissolving 0.350 mol of NaZ in sufficient water to yield 1.0 L of solution. The pH of the solution was 8.93 at 25.0°C. The Kb of Z- is __________.
C) 2.1 × 10-10
The acid-dissociation constant, Ka, for gallic acid is 4.57 × 10-3. What is the base-dissociation constant, Kb, for the gallate ion?
A) 4.57 × 10-3
B) 2.19 × 10-12
C) 5.43 × 10-5
D) 7.81 × 10-6
E) 2.19 × 102
The base-dissociation constant, Kb, for pyridine, C5H5N, is 1.4 × 10-9. The acid-dissociation constant, Ka, for the pyridinium ion, C5H5NH+, is __________.
A) 1.0 × 10-7
B) 1.4 × 10-23
C) 7.1 × 10-4
D) 1.4 × 10-5
E) 7.1 × 10-6
The Ka for HCN is 4.9 × 10-10. What is the value of Kb for CN-?
B) 4.0 × 10-6
C) 4.9 × 104
D) 4.9 × 10-24
E) 2.0 × 109
The base-dissociation constant of ethylamine (C2H5NH2) is 6.4 × 10-4 at 25.0 °C. The [H+] in a 1.6 × 10-2 M solution of ethylamine is __________ M.
A) 3.5 × 10-12
B) 2.9 × 10-3
C) 3.1 × 10-12
D) 3.2 × 10-3
E) 11.46
Calculate the pH of a 0.100 M aqueous solution of NH3. The Kb of NH3 is 1.77 × 10-5.
A) 8.95
B) 11.12
C) 2.88
D) 12.12
E) 1.87
The acid-dissociation constant of hydrocyanic acid (HCN) at 25.0°C is 4.9 × 10-10. What is the pH of an aqueous solution of 0.080 M sodium cyanide (NaCN)?
A) 11.11
B) 2.89
C) 1.3 × 10-3
D) 7.8 × 10-12
E) 3.9 × 10-11
Calculate the pH of 0.586 M anilinium hydrochloride (C6H5NH3Cl) solution in water, given that Kb for aniline is 3.83 × 10-4.
B) 12.18
C) 5.41
D) 8.59
E) 12.42
A solution of acetic acid is 2.0% dissociated at 25.0°C. What was the original concentration (in M) of the acetic acid solution? The Ka at 25.0 °C for acetic acid is 1.8 × 10-5.
A) 3.6 x 10-7
B) 0.045
C)
D)
What is the pH of a sodium acetate solution prepared by adding 0.820 grams of sodium acetate to 100.0 ml of water at 25.0°C? The Ka at 25.0°C for acetic acid is 1.8 × 10-5.
A) 8.87
B) 1.476 x 10-3
C) 2.87
D) 11.13
In the reaction
BF3 + F- → BF4-
BF3 acts as a Br∅nsted-Lowry acid.
True
False
An acid containing the COOH group is called a carbo-oxy acid.
A Lewis acid is an electron-pair acceptor, and a Lewis base is an electron-pair donor.
Por favor, aguarde! Carregando...