Ch.15 - Acid and Base EquilibriumSee all chapters
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Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
pH vs. pOH

The pH and pOH of a compound helps to determine its acidity and basicity. 

The pH Scale

Concept #1: Understanding pH vs. pOH. 

pH stands for the negative logarithmic function of your hydronium concentration, whereas pOH stands for the negative logarithmic function of hydroxide concentration. 

Concept #2: The connection to Hydronium ion and Hydroxide ion concentrations. 

If we know the pH or pOH concentration then we can determine the concentration of hydronium ions or hydroxide ions. 

Concept #3: The pH Scale. 

If the pH is less than 7 then the solution is acidic, if the pH is equal to 7 then the solution is neutral and if the pH is greater than 7 then the solution is basic. 

Concept #4: The pH and pOH connection. 

Under normal conditions when the concentration is less than 1.0 M the pH scale is between 0 to 14. pH and pOH are connected by the following equation: 

Example #1: What is the hydroxide ion and hydronium ion concentration of an aqueous solution that has a pH equal to 6.12?

Practice: Which of the following solutions will have the lowest concentration of hydronium ions?

Practice: Which of the following statements about aqueous solutions is/are true?

Example #2: A solution is prepared by dissolving 0.235 mol Sr(OH)2 in water to produce a solution with a volume of 750 mL.

 

a) What is the [OH-]?

 

b) What is the [H+]?

Practice: What is the Kw of pure water at 20.0°C, if the pH is 7.083?

Auto – Ionization Product

Concept #5: Understanding the Auto-Ionization Reaction.

In a self-ionization reaction two water molecules react with one another, where one acts an acid and the other as a base. 

The ionization product of Kw is used in this self-ionization equation and ignoring solids and liquids gives the  equilibrium equation as: 

Example #3: Determine the concentration of hydronium ions for a neutral solution at 25oC and at 50oC.

pH of Strong Acids and Bases

If we have a STRONG ACID or STRONG BASE then we DO NOT use an ICE chart to find the pH of solution because the yield of H+ and OH  ions are known. 

Concept #6: Calculating the pH of a Strong Acid or Strong Base. 

Example #4: Calculate the pH of a 0.0782 M solution of CaH2.  

Example #5: Calculate the pH of a 0.000550 M HBr solution to the correct number of significant figures.

  1. 3.3
  2. 3.26
  3. 3.260
  4. 3.2596
  5. All are correct

Practice: Calculate the pH of 50.00 mL of 4.3 x 10-7 M H2SO4.

pH of Weak Acids and Bases

If we have a WEAK ACID or WEAK BASE then we DO use an ICE chart to find the pH of solution because the yield of H+ and OH  ions are unknown. 

Concept #7: Calculating the pH of a Weak Acid or Weak Base. 

To determine the pH of a weak acid or weak base we must use an ICE Chart. 

Example #6: Pryridine, an organic molecule, is a very common weak base.

 

C5H5N (aq) + H2O (l)  ⇌  C5H5NH+ (aq) + OH- (g)

 

Assume you have a 0.0225 M aqueous solution of pyridine, C5H5N, determine its pH. The Kb value for the compound is 1.5 x 10-9

Example #7: An unknown weak base has an initial concentration of 0.750 M with a pH of 8.03. Calculate its equilibrium base constant. 

Practice: Determine the pH of a solution made by dissolving 6.1 g of sodium cyanide, NaCN, in enough water to make a 500.0 mL of solution. (MW of NaCN = 49.01 g/mol). The Ka value of HCN is 4.9 x 10-10.

Additional Problems
Calculate the hydroxide ion concentration in an aqueous solution with a pH of 9.85 at 25°C. A) 7.1 × 10-5 M B) 4.2 × 10-10 M C) 8.7 × 10-10 M D) 6.5 × 10-5 M E) 1.4 × 10-10 M
What is the hydronium ion concentration of an acid rain sample that has a pH of 3.45? A) 2.82 × 10-11 M B) 3.55 × 10-4 M C) 3.45 M D) 10.55 M
What is the hydroxide ion and hydronium ion concentration of an aqueous solution that has a pOH equal to 6.29?
Calculate the pH of water at 40 oC, given that Kw is 3.8 x 10 -14 at this temperature. 
At body temperature of 37.0°C, K w = 2.5 x 10-14. Calculate the [H3O+] if the [OH -] = 3.9 x 10-3 M. A. 2.5 x 10-12 M B. 6.4 x 10-12 M C. 3.9 x 10-3 M D. 1.0 x 10-7 M E. 2.5 x 10-14 M
A solution with pH of 2 has twice the [H+] as as solution of pH 4. a. True b. False
A beaker contains a solution with [H3O+] = 2.59 x 10 -2 M at 25°C. Which of the following statement(s) is/are correct about this solution? i. The [OH-] in solution equal to 3.86 x 10 -6 M. ii. The pOH of the solutions is 12.41. iii. The beaker contains an acidic solution. A. i only B. ii only C. iii only D. i and ii E. ii and iii
What is the [OH -] for a solution at 25°C that has [H 3O+] = 2.35 x 10 -3 M? A) 4.26 x 10-5 M               B) 2.35 x 10-11 M                  C) 4.26 x 10-12 M D) 2.35 x 10-17 M              E) None of these choices is correct.
Calculate the pH of a solution at 25°C in which the [OH−] = 5.4 x10  −7 M. A) 4.51 B) 7.05 C) 7.73 D) 6.38 E) 8.40
Calculate the pOH of a solution that contains 3.9 x 10 -4 M H3O+ at 25°C. A) 4.59 B) 3.31 C) 10.59 D) 9.14 E) 0.59
What is the [H3O+] for a solution at 25°C that has pOH = 5.640? A) 2.34 x 10-4 M B) 2.29 x 10-6 M C) 4.37 x 10-9 M D) 4.27 x 10-11 M E) 8.360 M
Calculate the hydroxide ion concentration in an aqueous solution with a pH of 4.33 at 25°C. A) 2.1 × 10-10 M B) 9.7 × 10-10 M C) 4.7 × 10-5 M D) 3.8 × 10-5 M E) 6.3 × 10-6 M
The pH of gastric juice inside the stomach is 1.5. What is [OH −]? Kw = 2.8 x10 -14 at body temperature (37 °C).
At 0 degrees Celsius, the ion product constant of water is 1.2x10-15. The pH of pure water at this temperature is:   A. 6.88 B. 7.00 C. 7.46 D. 7.56
What is the hydroxide concentration in a solution with a pH of 6.34?   A. 2.19x10-6 B. 2.19x10-8 C. 3.45x10-4 D. 3.45x10-6 E. 6.26x10-8
What is the hydronium ion concentration in a solution having a pOH of 3.62? 1. 3.8 × 10−5 M 2. 4.2 × 10−11 M 3. 3.8 × 10−4 M 4. 2.6 × 10−11 M 5. 5.1 × 10−10 M
For a solution that has a pH of 2.00, what is the concentration of OH  - ions? A. none present B. 0.0100 C. 1.00 x 10 −7 D. 1.00 x 10 −12 E. 1.00 x 10−16
What is the hydroxide ion and hydronium ion concentration of an aqueous solution that has a pH equal to 6.12?
If additional OH- is added to a sample of pure water, which of the following statements is incorrect?   a. The equilibrium position shifts to the left. b. The solution becomes more basic.  c. The [H3O+] remains unchanged. d. The [OH-] > [H3O+]. e. The amount of non-ionized H2O increases.  
What is the [H3O+] for a solution at 25°C that has pOH = 5.640? A) 2.34 x 10-4 M B) 2.29 x 10-6 M C) 4.37 x 10-9 M D) 4.27 x 10-11 M E) 8.360 M
Assuming equal concentrations, rank these solutions by pH from highest pH to lowest pH.  Sr(OH)2 (aq) NaOH (aq) NH3 (aq) HBrO (aq) HBr (aq)
At 0°C the ion product constant of water,  Kw, is 1.2 x 10–15. The pH of pure water at this temperature is (A) 6.88 (B) 7.00 (C) 7.46 (D) 7.56
Of the following, a solution with which pH would have the greatest concentration of hydronium ions? 1. 8  2. 9 3. 10 4. 12
Complete the following statement. A pH value of −1.5 1. indicates an H+ concentration of 31.6 M. 2. is impossible because pH cannot be negative. 3. indicates an H+ concentration of 0.0316M. 4. indicates an H+ concentration of −0.0176M. 5. indicates an H+ concentration of 0.176M. 6. indicates an H+ concentration of −0.0316M.
What is the [OH -] for a solution at 25°C that has [H 3O+ ] = 8.23 x 10 -2 M? A) ˃10-5 M B) 1.22 x 10-6 M C) 8.23 x 10-12 M D) 1.21 x 10-13 M E) 8.23 x 10-16 M
What is the concentration of hydroxide ions in pure water at 30.0°C, if K w at this temperature is 1.47 × 10-14? A) 1.00 × 10-7 M B) 1.30 × 10-7 M C) 1.47 × 10-7 M D) 8.93 × 10-8 M E) 1.21 × 10-7 M
Which answer is a true statement about pH values?a. A high pH value corresponds to a high H + concentration.b. Stomach acid has a high pH value.c. Pure water has a pH value of 0.d. pH is important in life mainly because it affects many everyday applications.e. None of the above.
Which of the following solutions is basic?i. [H3O+] = 2 x 10 -8 Mii. [OH-] = 2 x 10 -6 Miii. [H3O+] = 9 x 10 -6 Ma. i , ii, and iiib. iiic. iid. i and ii
What is the concentration (in M) of hydroxide ions (OH −) in a solution at 25.0 °C with pH = 4.282?      A) 9.72 B) 1.66 × 10 4 C) 1.91 × 10 −10 D) 5.22 × 10 −5 E) 4.28
pOH = 3.14 is equivalent to:       A) [OH −] = 3.14 × 10 −7 M B) pH = 11. C) [H +] = 1.4 × 10 −10 M D) [OH −] = 7.2 × 10 −4 M E) [H +] = 7.0 × 10 −4 M
Which is the pH of a solution with a [H  3O+] of 1 × 10 -9 M?a. -9.0b. 5.0c. -5.0d. 9.0e. None of the above 
What is the pH of an aqueous solution with the hydronium ion concentration [H  3O+] = 2 x 10 -14 M ?
If the concentration of hydronium ion, [H3O+] = 8.62 x 10 -4, what is the pH of the solution? a. 10.936 b. 0.998 c. 3.064 d.1.6 x 10-11 e. 2.329
For the following strong base solution, determine [OH-], [H3O+], pH, and pOH. 0.20M NaOH
Calculate the [H3O+] of a solution that has a pOH = 4.1.A. 1.3 x 10-10 MB. 9.9 MC. 7.9 x 109 MD. 2.4 x 10-15 ME. 4.1 x 10-11 M
Calculate the concentrations of H 3O+ and OH− in each of the following solutions: i) Human blood (pH 7.40) ii) A cola beverage (pH 2.8)
Presented below are the most important formulas for acids and bases. 
Which of these statements are true for a neutral, aqueous solution at 25 degree C? More than one can be correct.  a. pH = 7.00 b. pOH = 7.00 c. [H+] = [OH -] Which of these statements are true for a neutral, aqueous solution regardless of temperature? More than one can be correct.  a. pH = 7.00 b. pOH = 7.00 c. [H+] = [OH -]
For a solution with an [OH −] of 10−8 M, what would be the value of [H +] , pH and pOH, respectively? 1. 10−14 M, 6, 8 2. 10−6 M, 6, 8 3. 10−6 M, 8, 6 4. 106 M, 6, 8 5. 10−6 M, 6, 14 6. 10−14 M, 8, 6
Which statement correctly describes a solution with a pH of 9? a. It has a higher concentration of H 3O+ than OH - and causes litmus to turn blue. b. It has a higher concentration of OH - than H3O+ and causes litmus to turn blue. c. It has a higher concentration of H 3O+ than OH - and causes methyl orange to turn yellow. d. It has a higher concentration of OH - than H3O+ and causes methyl orange to turn red.
What is the pH of 8 x 10 -8 M HCl?
In an acidic solution, how does the concentration of hydronium ions compare to the concentration of hydroxide ions? a) Hydronium ion is greater than hydroxide ion. b) There is not enough information to tell. c) They are equal. d) Hydronium ion is less than hydroxide ion.
Which solution that has a pH of 2.00, what is the concentration of OH – ions?a. none presentb.0.0100c. 1.00 * 10–7d. 1.00 * 10–12e. 1.00 * 10–19
The lower the pH number, the higher is the hydrogen ion concentration.a. Trueb. False 
Which solution below has the highest concentration of hydroxide ions?a. pH= 3.21b. pH= 7.00c. pH= 7.93d. pH= 12.59e. pH= 9.82
Why is the pH of distilled water usually less than 7?
For the strong acid solution, determine [H 3O+], [OH-], and pH: 0.26M HCl 
In water, the equilibrium 2H2O(l) ⇌ H3O+ (aq) + OH−(aq)      Kc = 10−14 determines the concentrations of H3O+(aq) and OH -(aq). If the pH is 9.2, what is the OH - concentration? (note H3O+(aq) and H+(aq) are equivalent ways of representing a solvated proton and pH = -log[H+(aq)].) a) 9.76x10−6 b) 2.31x10−5 c) 3.88x10−4 d) 1.58x10−5 e) 2.54x10−6
Calculate [H3O+] and [OH−] for each of the following solutions. a. pH= 8.57  b. pH= 2.86
Complete the following table. All solutions are at 25°C. (Up to two significant figures)    
What is the pH of pure water at 40C if the kw at this temperature is 2.92x10-14?
For each of the following strong base solutions, determine [OH−],[H3O+], pH, and pOH.Express your answer using three significant figures. 8.74 × 10−3 M LiOHExpress your answer to three decimal places. [OH−],[H3O+] =Express your answer using three significant figures. 1.12 × 10−2 M Ba(OH)2Express your answer to three decimal places. [OH−],[H3O+] =Express your answer using three significant figures. 2.2 × 10−4 M KOHExpress your answer to three decimal places. [OH−],[H3O+] =Express your answer using three significant figures. 4.8 × 10−4 M Ca(OH)2Express your answer to three decimal places. [OH−],[H3O+] =
Arrange the following aqueous solutions, all at 25°C in order of decreasing acidity. a. pOH = 8.05 b. 0.0023M HCl c. pH= 5.45 d. 0.0018M KOH
If 1 mol of each of the following substances were dissolved in 1 L of water, which solution would contain the highest concentration of OH- ions?a. H2SO4b. NH4Clc. KNO3d. NaOH 
 Calculate the poH of a 0.0321 M HCIO4 solution at the following temperatures
What is the pH of a neutral solution at a temperature where Kw = 9.9 times 10-14? Express your answer numerically using two decimal places.
What are the concentrations of OH- and H+ in a 0.00052 M solution of Ba(OH)2 at 25°C? Assume complete dissociation. [OH-] = [H+] =
A patient with respiratory alkalosis has a blood plasma pH of 7.59. What is the [H3O+] of the blood plasma? Express your answer to two significant figures and include the appropriate units.
Calculate either [H3O+] or [OH-] for the solutions below. a) [OH-] = 3.21 x 10-7 M b) [H3O+] = 9.73 x 10-9 M c) [H3O+] = 0.000551 M Which of these solutions are basic at 25°C?
Calculate the H3O+ concentration for each pH: a) pH = 13b) pH = 2 c) pH = 8 
Calculate the [H3O+] and pH of each of the following H2SO4 solutions.Calculate the [H3O+] for 0.10 M solution. Express your answer using two significant figures. Calculate pH for 0.10 M solution. Express your answer using two decimal places.
Calculate [H30+] for the following solutions:a) 6.00 x 10 3 M HBrb) 1.80 x10-2 M KOH
The Kw for water at 0 C is 0.12 x 10^-14. Calculate the pH of a neutral aqueous solution at 0 C. ls a pH = 7.25 solution acidic, basic, or neutral at 0 C? 
(a) What is the pH of 3.7 times 10^-3 M HCI? (b) What is the pH of 8 times 10^-8 M HCI?
Calculate the pH and the pOH of an aqueous solution that is 0.035 M in HCl (aq) and 0.060 M in HBr(aq) at 25 C. 
0.90 g of sodium hydroxide (NaOH) pellets are dissolved in water to this solution? Express the pH numerically to two decimal places. pH = 11.75 What is the pOH of the solution in Part B? Express the pOH numerically to two decimal places.
Three solutions have the following pH:a) pH = 4.3b) pH = 6.8c) pH = 11.5 Which solution contains the highest H3O+ ion concentration?Which solution is the most acidic?Which solution is the most basic?2. What is the difference between a strong acid and a weak acid?3. Calculate [H3O+] and [OH-] for the following three solutionsa) pH = 9.5b) pH = 3.6c) pH = 7.0
At 25 C, how many dissociated OH ions are there in 1219 mL of an aqueous solution whose pH is 1.56? 
Complete this table of values for three aqueous solutions at 25 c.
What is the concentration of OH - in a 0.1 M solution of HI? 1 x 10-12 M 0.1 M 1 x 10-13 M 0.00001 M
Calculate either [H3O+] or [OH -] for the solution below. Which of these solutions are basic at 25°C?
What is the pH of an aqueous solution with a hydrogen ion concentration of [H+] = 7.3 times 10-9 M?
Calculate the [H3O+] of each aqueous solution with the following [OH-].Part A         NaOH, 1.0 x 10-2 M         Express your answer using two significant figures.Part B          milk of magnesia, 1.2 x 10-5 M           Express your answer using two significant figures.
Calculate the pH of the following aqueous solutions at 25°C, K w at 25°C is 1.01e-14. (a) 3.2 x 10-11 M KOH ___________ (b) 7.6 x 10-7 M HNO3 _________
Calculate the pH and the pOH of an aqueous solution that is 0.040 M in HCl(aq) and 0.055 M in HBr(aq) at 25°C.
Calculate the pOH of a 0.0448 M HCIO4 solution at the following temperatures. a) 5°Cb) 45°C
Part AIf the [H3O+] is 4.950 x 10-12, what is the pH? (i) -11.305 (ii) 11.3 (iii) 2.020 x 10-12 (d) 11.305
Calculate the hydronium ion, H3O+, and hydroxide ion, OH-, concentrations for a 0.0244 M HCI solution. [H3O+] = [OH-] = 
Complete this table of values for three aqueous solutions at 25°C.
Calculate the pH of an aqueous solution that is 0.020 M in HCl (aq) at 25°C.  
Determine the concentration of H+ in the following solutions at 25°C: a) a solution with pH = 2.0 [H+] =  b) a solution  [H+] =  c) a solution with pOH = 10.0 [H+] = 
Complete this table of values for three aqueous solutions at 25°C.
What is the pH of a 3.0 M solution of HCIO4?
What are [H3O+], [OH-], and pOH in a solution with a pH of 3.22? 
The pH scale was designed to make it convenient to express hydrogen ion concentrations that are small in aqueous solutions. The definition of pH is in terms of base 10 logarithms. pH = - log [H +] where [H+] is the hydrogen ion concentration. (A) If the hydrogen ion concentration in a solution is 1.36 x 10 -3 mol/L the pH is __________. (B) If the pH of a solution is 4.108, the hydrogen ion concentration is _________ mol/L.
Calculate [H+], and [OH-] in an aqueous solution that is 0.115 M in HCLO 4(aq) at 25°C. Is the solution acidic, basic or neutral? 
What is the pH of a solution that has a [H+] = 0.0045 M? Select one: a. 2.35 b. None of these c. 1.35 d. 7.0045 e. 3.35
Calculate [OH-] for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral. [H+] = 6.5 x 10-10 M. Express your answer using two significant figures.
Given that KN for water is 2.4 x 10-14 M2 at 37 °C, Compute the pH of a neutral aqueous solution at 37 °C, which is the normal human body temperature.Is a pH = 7.00 solution acidic, basic, or neutral at 37 °C? 
Question 2Calculate the pH of a solution with [OH-] equal to 2.9 x 10-4 M. 
Calculate either [H3O+] or [OH -] for the solutions below at 25°C. a) [OH-] = 1.21 x 10-7 M b) [H3O+] = 8.05 x 10-9 M c) [H3O+] = 0.000589 MWhich of these solutions are basic at 25°C? 
A solution has a pH of 3 and another has a pH of 7. What is true? (a) The pH 3 has more Hydrogen ions than the pH7 and is an acid. (b) The pH 7 is neutral and has more H+ ions than the pH3. (c) pH 3 is a base and pH 7 is neutral
The question has multiple parts. Work on all the parts to get the most points.Determine the [H+] value for solutions with the following characteristics: a. pH = 9.59 b. pH = 2.40 c. pH = 5.39 
Calculate the pH of a 0.03 M solution of Ca(OH)2. Select one: a. 1.48 b. 12.52 c. 1.18 d. 12.82 e. None of these
Calculate the pH of a 0.0477 M KOH solution at the following temperatures.a) 10°Cb) 50°C
To calculate pH and use it as a measure of acidity. The pH expresses the molar concentration of hydronium ions in an aqueous solution on a logarithmic scale: pH = -log[H3O+] [H3O+] = 10-pH As pH decreases, acidity increases. As pH increases, acidity decreases. Acidic solution: pH < 7; Neutral solution: pH = 7; Basic solution: pH > 7Carbonated cola is more acidic than coffee or even orange juice because cola contains phosphoric acid What is the molar concentration of H3O+ in a cola that has a pH of 4.240? Express your answer with the appropriate units. Rank the following from most to least acidic. Rank from most to least acidic. To rank items as equivalent, overlap them.
Calculate the pH of each of the following strong acid solutions. Part A8.90 x 10-3 M HNO3. Express your answer using three decimal places.Part B0.600 g of HClO4 in 2.90 L of solution. Express your answer using three decimal places. 
A solution of NaOH(aq) contains 6.6 g of NaOH(s) per 100.0 mL of solution. Calculate the pH and the pOH of the solution at 25°C. pH = pOH = 
Calculate [H3O+] given [OH -] in each aqueous solution. Part A[OH -] = 6.1 x 10 -11 M Express your answer using two significant figures. Part BClassify this solution as acidic or basic. Part C[OH -] = 7.0 x 10 -9 M Express your answer using two significant figures.
Calculate pH for each H3O+ concentration: a) [H3O+] = 1 x 10-6 M b) [H3O+] = 0.001 M c) [H3O+] = 1 x 10-12 M
The hydronium ion concentration of an aqueous solution of 0.348 M formic acid, HCOOH (Ka = 1.80 x 10-4) is 
[OH-] = 5.5 x 10-9 M Express the molarity to two significant figures. 
A patient with respiratory alkalosis has a blood plasma pH of 7.58. What is the [OH  -] of the blood plasma? Express your answer to two significant figures and include the appropriate units.
Calculate the pH and the pOH of an aqueous solution that is 0.050 M in HCl(aq) and 0.060 M in HBr(aq) at 25°C.
Calculate the pH of each of the following strong acid solutions. Part C5.00 mL of 1.50 M HCl diluted to 0.530 L. Express your answer using three decimal places. Part DA mixture formed by adding 45.0 mL of 2.5 x 10-2 M HCl to 150 mL of 1.5 x 10-2 M HI. Express your answer using two decimal places. 
You have a solution with a hydronium ion concentration of 1.0 times 10 -7 M. What is the hydroxide ion concentration in this beaker? a. 0.01 Mb. 1 x 10-12 Mc. 12 M d. 2 Me. 1 x 10-7 Mf. 1 x 10-10 M  
What are the H3O+ and OH- concentrations of solutions that have the following pH values? Part ApH3 Express your answer using one significant figure separated by a comma.
What are the concentrations of H 3O+ and OH- in oranges that have a pH of 3.76? 
Be sure to answer all parts.What are [H3O+], [OH -], and pOH in a solution with a pH of 11.50? 
At 25°C, what is the hydroxide ion concentration, [OH-], in an aqueous solution with a hydrogen ion concentration of [H+] = 2.4 x 10-9 M? 
What is the concentration of OH- and pOH in a 0.00058 M solution of Ba(OH)2 at 25°. Assume complete dissociation. [OH-] =pOH =  
Calculate the pH of a 0.0279 M HCl solution. Your answer should be to the nearest tenth.
Ba(OH)2 is a strong electrolyte. Determine the concentration of each of the individual ions in a 0.750 M Ba(OH)2 solution.
Calculate [H3O+] for the following solutions:a. 3.44 x 10-3 M HBr[H3O+] = b. 1.50 x 10-2 M KOH[H3O+] =  
Calculate [H+] for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral. Part A[OH-] = 5.5 x 10-4 M. Express your answer using two significant figures. Part B                       • the solution is acidic                       • the solution is basic                        • the solution is neutral    
Calculate the [OH-] of peas with the [H3O+] = 5.5 times 10-7 M
Calculate [H+], [ClO4-], and [OH-] in an aqueous solution that is 0.125 M in HClO 4(aq) at 25°C. Is the solution acidic, basic or neutral? 
Complete this table of values for four aqueous solutions at 25°C.
Complete this table of values for four aqueous solutions at 25°c 
An aqueous solution at 25 degree C has a H3O+ concentration of 0.0076 M. Calculate the OH- concentration. Be sure your answer has the correct number of significant digits.
What are the concentrations of hydrogen ion and hydroxide ion in household ammonia, an aqueous solution of NH3 that has a pH of 12.3?