Chem Unit 9
pH is -log [H3O+] log OH- [H3O+] antilog [H3O+]
-log [H3O+]
A 25.00 mL sample of H 2SO 4 is used in a titration experiment with a 0.118 M solution of NaOH. The volume of the NaOH solution needed to reach the equivalence point of the titration is 17.35 mL. What is the concentration of the H 2SO 4 solution. The chemical equation for the reaction is below. H 2SO 4 + 2 NaOH ---> 2 H 2O + Na 2SO 4 0.0819 M 0.164 M 0.0409 M 0.236 M
0.0409 M
A 25.00 mL sample of HCl is used in a titration experiment with a 0.0512 M solution of NaOH. The volume of the NaOH solution needed to reach the equivalence point of the titration is 21.68 mL. What is the concentration of the HCl solution. The chemical equation for the reaction is below. HCl + NaOH ---> H 2O + NaCl 0.0444 M 0.0590 M 0.0295 M 0.0148 M
0.0444M
In a particular titration experiment, a 25.0 mL sample of H 3PO 4 requires 30.0 mL of a 0.200 M NaOH solution to reach the equivalence point. What is the concentration of the H 3PO 4? The chemical equation for this titration is shown below. H 3PO 4 + 3 NaOH ---> Na 3PO 4 + 3 H 2O 0.120 M 0.167 M 0.240 M 0.0800 M
0.0800 M
In a particular titration experiment, a 25.0 mL sample of HC 2H 3O 2 requires 30.0 mL of a 0.200 M NaOH solution to reach the equivalence point. What is the concentration of the HC 2H 3O 2? The chemical equation for this titration is shown below. HC 2H 3O 2 + NaOH ---> NaC 2H 3O 2 + H 2O 0.120 M 0.167 M 0.240 M 0.333 M
0.240 M
What is the hydronium ion concentration of a solution that has a pH of 6.0? 1 x 10-6 M 6x 106 M 1 x 10-1 M 6 x 10-14 M
1 x 10-6 M
What is the hydronium ion concentration in pure water? 1.0 x 10-14 M 1.0 x 10-7 M 1.0 x 107 M 1.0 x 1014 M
1.0 x 10^-7 M
What is the hydroxide ion concentration in pure water? 7.0 x 10-7 M 1.0 x 10-14 M 1.0 x 10-7 M Pure water does not have any hydroxide ion. The concentration is zero
1.0 x 10^-7 M
Calculate the hydroxide ion concentration of a solution having a pH value of 9.05. 7.49x10-3 M 8.91x10-10 M 3.89x10-11 M 1.12x10-5 M 8.51x10-4 M
1.12x10-5 M
What is the hydronium ion concentration of sea water which has a pH of 8? 8 x 10-1 M 1.1 x 10-8 M 7.9 x 10-9 M 1.2 x 10-7 M
1.1x 10-8 M
What is the hydronium ion if the solution has a hydroxide ion concentration of 8.1 x 10 -2? 8.1 x 1012 8.1x 10-16 1.2 x 10-13 1.2 x 1015
1.2 x 10-13
An aqueous solution has a hydroxide ion concentration equal to 5.70 x 10 -3 M. What is the H + concentration in this solution? 5.7 x 10-17 M 8.77 x 10-11 M 3.08 x 10-10 M 8.77 x 10-13 M 1.75 x 10-12 M
1.75 x 10-12 M
The K a values for four acids are listed below. Which K a is the value for the strongest acid? 1.8 x 10-10 5.6 x 10-11 1.8 x 10-4 7.8 x 10-6
1.8 x 10 ^-4
Household ammonia has a pH of 9.25. What is the molar concentration of the hydroxide ion in ammonia? 9.25 1.8 x 10-5 1 x 10-7 1.8 x 10-9 5.6 x 10-10
1.8 x 10^-5
A solution has a hydroxide concentration of 1.0 x 10 -4 M. What is the pH of this solution? 4.00 7.00 6.00 10.00
10.00
The hydroxide ion concentration of a solution of a base is 0.001 M. The pH of the solution is 4 12 8 11
11
You have an aqueous solution that has a hydronium ion concentration of 5 x 10 -6 M. What is the hydroxide concentration of this solution? 2 x 10-10 M 2 x 10-9 M 2 x 10-8 M 2 x 107 M
2 x 10-9 M
A solution has a hydronium ion concentration of 6.0 x 10 -3 M. What is the pH of this solution? 2.22 3.60 11.78 5.12
2.22
What is the hydroxide ion concentration in a solution if the solution has a hydronium ion concentration of 4.3 x 10 -4? 2.3 x 1017 4.3 x 1010 2.3 x 10-11 2.3 x 10-19
2.3 x 10 ^-11
An aqueous solution has a hydronium concentration equal to 0.0045 M. What is the pH of this solution? 4.17 2.35 3.35 5.35 10.0
2.35
What is the pH of a solution that has a hydronium ion concentration of 2.6 x 10 -3? 2.6 -2.6 11.4 -11.4
2.6
The K a for lactic acid is 1.4 x 10 -4. What is the pK a of lactic acid? -10.92 -3.85 3.85 10.92
3.85
You perform four separate titration experiments with 0.5 M NaOH solution and the following acid samples. Which acid sample will require the largest volume of NaOH to complete the titration? 10 mL of a 0.20 M HCl solution 20 mL of a 0.30 M HCl solution 30 mL of a 0.30 M HCl solution 40 mL of a 0.20 M HCl solution 0 mL of a 0.20 M HCl solution 20 mL of a 0.30 M HCl solution 30 mL of a 0.30 M HCl solution 40 mL of a 0.20 M HCl solution
30 mL of a 0.30 M HCl solution
You have 4.0 moles of LiOH in a beaker. How many moles of HBr must you add to the beaker to completely neutralize the LiOH based on the following chemical equation? HBr + LiOH ---> H2O + LiBr 0.50 1.0 2.0 4.0
4.0
What is the hydroxide ion concentration of aqueous solution with a hydronium ion concentration of 2.50 x 10 -10 M? 4.0 x 10-24 2.5 x 10-5 4.0 x 10-5 2.5 x 10-4 2.5 x 104
4.0 x 10 ^-5
What is the pH of soda pop with a hydrogen ion concentration of 6.0 x 10 -5 M? 5 5.22 4.78 4.22 4
4.22
What is the pH of a solution that has hydronium ion concentration equal to 4.98 x 10 -5 M? 7.30 9.7 -4.30 4.30
4.30
A solution has a pH of 1.23. What is the hydronium ion concentration of this solution? 5.9 x 10-2 1.7 x 10-13 5.9 x 10-1 1.9 x 10-11
5.9 x 10-2
You perform four separate titration experiments with 0.5 M NaOH solution and the following acid samples. Which acid sample will require the largest volume of NaOH to complete the titration? 25 mL of a 0.20 M HCl solution 50 mL of a 0.10 M HCl solution 25 mL of a 0.30 M HCl solution 50 mL of a 0.20 M HCl solution 25 mL of a 0.20 M HCl solution 50 mL of a 0.10 M HCl solution 25 mL of a 0.30 M HCl solution 50 mL of a 0.20 M HCl solution
50 mL of a 0.20 M HCl solution
You perform four separate titration experiments with 0.5 M NaOH solution and the following acid samples. Which acid sample will require the largest volume of NaOH to complete the titration? 25 mL of a 0.50 M HCl solution 50 mL of a 0.50 M HCl solution 25 mL of a 0.25 M HCl solution 50 mL of a 0.25 M HCl solution 25 mL of a 0.50 M HCl solution 50 mL of a 0.50 M HCl solution 25 mL of a 0.25 M HCl solution 50 mL of a 0.25 M HCl solution
50 mL of a 0.50 M HCl solution
An aqueous solution has a H + molar concentration equal to 3.4 x 10 -9. What is the pH of this solution? 3.40 8.47 9.53 -0.53
8.47
What is the pH of a solution whose hydronium ion concentration is 2.6 x 10 -9? 5.41 8.59 14.00 2.69
8.59
The K a of phenol is 1.3 x 10 -10. What is the pK a of phenol? 9.89 -9.89 13.0 -13.0
9.89
The K a of phenol is 1.3 x 10 -10. What is the pK a of phenol? 9.89 -9.89 13.0 -13.0
9.89
The pK a values for four acids are listed below. Which pK a is the value for the weakest acid? 4.75 9.89 5.43 3.87
9.89
A substance that forms hydroxide ions (OH -) in water and/or accepts protons (H +) is classified as which of the following? An acid A base A neutralization A solution
A Base
A substance that can behave as either an acid or a base is: anthocyanin a neutral substance an indicator an amphiprotic substance
An amphiprotic substance
Which of the following solutions has the highest hydroxide ion concentration? A 0.2 M solution of HCl A 0.2 M solution of H2SO4 Pure water An aqueous solution with pH 8
An aqueous solution with pH 8
Which of the following materials will react with an acid to produce a gas? An active metal Sodium carbonate Both an active metal and sodium carbonate None of the materials listed above will react with an acid to produce a gas
Both an active metal and sodium carbonate
Which of the following materials will react with an acid to produce a gas? An active metal Sodium carbonate Both an active metal and sodium carbonate None of the materials listed above will react with an acid to produce a gas.
Both an active metal and sodium carbonate
Which statement below about acids and bases is true? A Bronsted-Lowry acid is a proton donor. A Bronsted-Lowry base is a proton acceptor. Both statements listed above are correct.
Both statements listed above are correct
Consider the reversible chemical reaction shown below. What is the conjugate acid of C 6H 5O - in this reaction? C 6H 5OH + H 2O <---> H 3O + + C 6H 5O - C6H5OH H2O H3O+ C6H5O-
C6H5OH
Which of the following forms when a strong acid reacts with sodium bicarbonate? Sodium chloride Carbonic acid A strong base The ammonium ion
Carbonic acid
What are the conjugate acid and conjugate base of HCO 3 -? Conjugate acid: H3+; conjugate base: OH- Conjugate acid: H2CO3; conjugate base: CO32- Conjugate acid: CO32-; conjugate base: H2CO3 Conjugate acid: OH-; conjugate base: H3+ None of these
Conjugate acid: H2CO3; conjugate base: CO32-
Balance the chemical equation shown below. How many moles of HI would be needed to completely react with four moles of Ba(OH)2? HI + Ba(OH)2 ---> BaI2 + H2O Two Four Six Eight
Eight
A solution that has a pH equal to zero (0) is considered a neutral solution. True False
False
Acetic acid (HC 2H 3O 2) is a weak acid. The correct expression for the acid ionization constant (K a) for this acid is shown below. [H3O-][C2H3O2-]/ [HC2H3O2][H2O] True False
False
All strong acids must have a concentrations in solution greater than 1.0 M. True False
False
Every titration experiment, regardless of the acid and base you are using, will have the same pH at the equivalence point. True False
False
H 2O is behaving like an acid in the reaction shown below. HClO3 + H2O <--> ClO3- + H3O+ True False
False
Hydrocyanic acid (HCN) is a weak acid. The correct expression for the acid ionization constant (K a) for this acid is shown below. [HCN]/[H3O+][CN-]=Ka true false
False
Hydrofluoric acid (HF) is a weak acid. The correct expression for the acid ionization constant for hydrofluoric acid is as follows. [HF][F-] /[H3O+] = K3 True False
False
If the pH of a solution is 11.81 the hydroxide ion concentration of that solution is 1.5 x 10 -12. True False
False
NH 4 + is behaving like a base in the reaction below. NH4+ + H2O <--> NH3 + H30+ True False
False
The chemical reaction shown below takes place when you add HBr to water. When the reaction is done there are no HBr molecules in the water. This means that HBr is a weak Bronsted acid. HBr + H2O <--> Br- + H3O+ True False
False
The chemical reaction shown below takes place when you add HCN to water. When the reaction is done there are still some HCN molecules in the water. This means that HCN is a strong Bronsted acid HCN + H2O <--> CN- + H3O+ True False
False
The hydrogen ion (H +) and the nitrate ion (NO 3 -), when mixed together, can form an acid-base buffer. True False
False
The reaction shown below is an example of a neutralization reaction. HCO2- +h+ <--> HCO2H true false
False
The reaction shown below is an example of a neutralization reaction. HClO3 + H2O <--> ClO3- + H3O+ True False
False
The reversible chemical reaction shown below takes place when you add the formate ion (HCO 2 -) to water. The formate ion is behaving like a weak acid in this reaction. HCO2- + H2O <--> HCO2H + OH- True False
False
The sodium ion (Na +) and the chloride ion (Cl -), when mixed together, can form an acid-base buffer. True False
False
You can make an acid-base buffer by mixing the ammonium ion (NH 4 +) with the nitrate ion (NO 3 -) in water. True False
False
You can make an acid-base buffer by mixing the sodium ion (Na +) and the hydroxide ion (OH -) together in water. True False
False
What is the formula for carbonic acid? HCO2 HCO3 H2CO3 H2CO2
H2CO3
Consider the reversible chemical reaction shown below. What is a base in this reaction? C 6H 5OH + H 2O <---> H 3O + + C 6H 5O - C6H5OH H2O H3O+ none of these
H2O
Consider the reversible chemical reaction shown below. What is the conjugate acid to OH - in this reaction? NH 3(g) + H 2O(aq) <---> NH 4 +(aq) + OH -(aq) H2O NH3 OH- NH4+
H2O
Hydrochloric acid (HCl) reactions with lithium hydroxide (LiOH). Which is a product of this reaction? H2O Hydrogen gas (H2) Carbon dioxide (CO2) None of the compounds listed above will be products of the reaction.
H2O
Sulfuric acid (H 2SO 4) reacts completely with sodium hydroxide (NaOH). What is the balanced chemical equation for this reaction? H2SO4 + NaOH ---> Na2SO4 + H2O H2SO4 + NaOH ---> NaHSO4 + H2O H2SO4 + 2 NaOH ---> Na2SO4 + 2 H2O Sodium hydroxide and sulfuric acid can't react completely with each other.
H2SO4 + 2 NaOH ---> Na2SO4 + 2 H2O
Consider the reversible chemical reaction shown below. What is the conjugate acid of H 2O in this reaction? C 6H 5OH + H 2O <---> H 3O + + C 6H 5O - C6H5OH H2O H3O+ C6H5O- none of these
H3O+
Which one of the following is a conjugate acid-base pair? H2O and O2- HCl and H+ NaOH and Na+ HCO3- and CO32-
HCO3- and CO3 2-
Consider the following chemical reaction. What is the proton donor in this reaction? HCl(g) + H 2O (l) ---> H 3O +(aq) + Cl -(aq) H2O HCl H3O+ Cl- none of the above
HCl
Consider the following chemical reaction. What is the proton donor in this reaction? HCl(g) + H 2O (l) ---> H 3O +(aq) + Cl -(aq) H2O HCl H3O+ Cl- none of the above
HCl
Given the following information, determine which acid is the strongest? Ka for boric acid 7.3 x 10-10 pKa for acetic acid is 4.75 Ka for lactic acid is 1.4 x 10-4 pKa for phenol is 9.89 Boric acid Acetic acid Lactic acid Phenol
Lactic acid
Which of the following is likely to behave as a Bronsted acid? HCl NaOH H2SO4 More than one response is correct
More than one response is correct
Which of the following is likely to behave as a Bronsted acid? HCl NaOH H2SO4 More than one response is correct
More than one response is correct
Consider the reversible chemical reaction shown below. What is the conjugate base of NH 4 + in this reaction? NH4+ + H2O <--> NH3 + H3O+ NH4+ H3O+ NH3 NH4+ does not have a conjugate base in this reaction
NH3
Which of the following is likely to behave as a Bronsted base? HCl NaOH NaCl More than one response is correct
NaOH
The reaction of an acid with a base is called a ________________ reaction. (Fill in the blank). neutralization precipitation oxidation-reduction combustion
Neutralization
Which of the following materials will react with an acid to produce a gas? Sodium hydroxide Water Both sodium hydroxide and water None of the materials listed above will react with an acid to produce a gas
None of the materials listed above will react with an acid to produce a gas
Which of the following materials will react with an acid to produce a gas? Lithium hydroxide Ammonia Lithium hydroxide and ammonia None of the materials listed above will react with an acid to produce a gas
None of the materials listed above will react with an acid to produce a gas
The hydronium ion concentrations of five different solutions are shown below. Which solutions are acidic? Solution A = 1.5 x 10 -1 M Solution B = 1.5 x 10 -3 M Solution C = 1.5 x 10 -4 M Solution D = 1.5 x 10 -7 M Solution E = 1.5 x 10 -11 M All of the solutions are acidic. Only solutions A, B, C and D are acidic. Only solutions A, B and C are acidic. Only solution E is acidic.
Only solutions A, B, C and D are acidic
Which of the following materials will react with an acid to produce carbon dioxide? An active metal Sodium bicarbonate (NaHCO3) Sodium hydroxide (NaOH) Ammonia (NH3)
Sodium bicarbonate (NaHCO3)
Solutions with different hydronium ion concentrations are shown below. Which solution is the most acidic? Solutions with [H3O+] =1 x 10-1 Solutions with [H3O+] =1 x 10-5 Solutions with [H3O+] =1 x 10-7 Solutions with [H3O+] =1 x 10-9 Solutions with [H3O+] =1 x 10-13
Solutions with [H3O+] =1 x 10-1
Solutions with different pH values are shown below. Which solution is most basic? Solutions with pH=1 Solutions with pH=5 Solutions with pH=7 Solutions with pH=9 Solutions with pH=13
Solutions with pH=13
A titration experiment is generally performed to determine which of the following? The identity of a particular acid or base The concentration of a particular acid or base The pH of a particular acid or base The Ka of a particular acid or base.
The concentration of a particular acid or base
Consider the chemical reaction shown below. Which statement(s) about this reaction is true? HF + H2O <--> F- + H3O+ The conjugate base of F- is HF. The conjugate acid of F- is HF. The conjugate base of F- is H2O. None of the statements listed above are correct
The conjugate acid of F- is HF.
Which of the following is true about an aqueous solution that has a pH equal to 7. It contains more OH- ions than H3O+ ions. It contains more H3O+ ions and OH- ions. The number of OH- ions is equal to the number of H3O+ ions. The number of OH- ions and H3O+ ions depends on the solute dissolved in the solution.
The number of OH- ions is equal to the number of H3O+ ions.
When determining the relative strengths of two weak acids, which factor should you compare to determine which is the stronger of the two? The formula weights of the two acids The concentrations of the two acids The pKa values of the two acids None of the factors listed above should be used to determine which acid is the strongest
The pKa values of the two acids
An aqueous solution has a hydronium concentration equal to 9.74 x 10 -2 M. This solution is acidic. True False
True
ClO 3 - is behaving like a base in the reaction shown below. HClO3 + H2O <---> ClO3- +H3O+ True False
True
F - is acting like an base in the reaction below. HF + H2O <--> F- + H3O+ True False
True
H 2O is acting as a base in the reaction below: CH3COOH + H2O <--> CH3COO- + H30+ True False
True
H 3O + is behaving like an acid in the reaction shown below. NH4+ + H2O <--> NH3 + H30+ True False
True
HF is acting like an acid in the reaction below. HF + H2O <--> F- + H3O+ True False
True
In the generalized shown below, the BH + is acting like an acid BH+ +H2O <--> B + H3O+ True False
True
The chemical equation below correctly shows a neutralization reaction. HCl + LiOH ----> LiCl + H2O True False
True
The phosphate ion (PO 4 3-) and the hydrogen phosphate ion (HPO 4 2-), when mixed together, can form an acid-base buffer. True False
True
The reversible chemical reaction shown below takes place when you add the nitrite ion (NO2-) to water. The nitrite ion is behaving like a weak base in this reaction. NO2- + H2O <--> HNO2 + OH- True False
True
You can make an acid-base buffer by mixing the acetate ion (C 2H 3O 2 -) and acetic acid (HC 2H 3O 2) together in water. True False
True
You can make an acid-base buffer by mixing the ammonium ion (NH 4 +) and ammonia (NH 3) together in water True False
True
You can make an acid-base buffer by mixing the carbonate ion (CO 3 2-) and the hydrogen carbonate ion (HCO 3 -) together in water. True False
True
You completely neutralize chromic acid, H2CrO4, with sodium hydroxide, NaOH. (See the chemical equation below.) The products that are formed in the reaction are Na2CrO4 and H2O. H2CrO4 + NaOH -----> True False
True
Which set of data is consistent with a single aqueous acidic solution? [H3O+] = 1 x 10-11, [OH-] = 1 x 10-11, pH=11 [H3O+] = 1 x 10-3, [OH-] = 1 x 10-11, pH=3 [H3O+] = 1 x 10-3, [OH-] = 1 x 10-3, pH=3 [H3O+] = 1 x 10-11, [OH-] = 1 x 10-3, pH=1 [H3O+] = 1 x 10-7, [OH-] = 1 x 10-7, pH=7
[H3O+] = 1 x 10-3, [OH-] = 1 x 10-11, pH=3
The difference between a strong and weak acid is that the strong acid ionizes __, whereas the weak acid ionizes __. completely, not at all completely, slightly slightly, completely slightly, not at all
completely, slightly
Carbonic acid _________________. (Fill in the blank) decomposes to form hydrogen gas. decomposes to form carbon dioxide gas. decomposes to form an ionic compound. decomposes to form ammonia.
decomposes to form carbon dioxide gas
