Chem 2 Unit 8
pH is
-log [H3O+]
In a particular titration experiment, a 25.0 mL sample of H3PO4 requires 30.0 mL of a 0.200 M NaOH solution to reach the equivalence point. What is the concentration of the H3PO4? The chemical equation for this titration is shown below. H3PO4 + 3NaOH --- Na3PO4 + 3H2O
0.0800
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.
0.240 M
What is the hydroxide ion concentration in pure water?
1.0*10^-7 M
What is the hydronium ion concentration of sea water which has a pH of 8?
1.1 x 10-8 M
Calculate the hydroxide ion concentration of a solution having a pH value of 9.05.
1.12x10^-5 M
If the pH of a solution is 3.81, what is the hydronium ion concentration of the solution?
1.5*10^-4
An aqueous solution has a hydroxide ion concentration equal to 5.70 x 10 -3 M. What is the H + concentration in this solution?
1.75 x 10^-12 M
You have 5.0 moles of H2SO4 in a beaker. How many moles of CsOH must you add to the beaker to completely neutralize the H2SO4 based on the following chemical equation?
10.0 moles
The hydroxide ion concentration of a solution of a base is 0.001 M. The pH of the solution is
11
An aqueous solution has a hydronium concentration equal to 0.0045 M. What is the pH of this solution?
2.35
You have 6.0 moles of HI in a beaker. How many moles of Mg(OH)2 must you add to the beaker to completely neutralize the HI based on the following balanced chemical equation?
3.0 moles
The Ka for lactic acid is 1.4 x 10^-4. What is the pKa of lactic acid?
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
30 mL of a 0.30 M HCl solution
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^-5
What is the pH of soda pop with a hydrogen ion concentration of 6.0 x 10^-5 M?
4.22
An aqueous solution has a H + molar concentration equal to 3.4 x 10 -9. What is the pH of this solution?
8.47
What is the pH of a solution whose hydronium ion concentration is 2.6 x 10^-9?
8.59
You dissolve sodium hydroxide (NaOH) in water. What is the likely result of this?
A lower [H+] of the solution.
Which of the following solutions has the highest hydroxide ion concentration?
An aqueous solution with pH 8
Which of the following materials will react with an acid to produce a gas?
Both an active metal and sodium carbonate
What are the conjugate acid and conjugate base of HCO3-?
Conjugate acid: H2CO3; conjugate base: CO32-
A solution that has a pH equal to zero (0) is considered a neutral solution.
False
All strong acids must have a concentrations in solution greater than 1.0 M.
False
An aqueous solution that has a hydroxide concentration equal to 2.0 x 10^-5 M is an acidic solution.
False
Hydrofluoric acid (HF) is a weak acid. The correct expression for the acid ionization constant for hydrofluoric acid is as follows.
False
If the pH of a solution is 11.81 the hydroxide ion concentration of that solution is 1.5 x 10^-12.
False
The reaction shown below is an example of a neutralization reaction. CH3CO2Na---CH3CO2_+Na+
False
The sodium ion (Na +) and the chloride ion (Cl -), when mixed together, can form an acid-base buffer.
False
You can make an acid-base buffer by mixing the lithium ion (Li +) and the sulfate ion (SO 4 2-) together in water.
False
What is the formula for carbonic acid?
H2CO3
Hydrochloric acid (HCl) reactions with lithium hydroxide (LiOH). Which is a product of this reaction?
H2O
Consider the reaction shown below. What is the conjugate acid of H 2O in this reaction?
H3O+
Consider the reaction shown below. What is the conjugate acid of H 2O in this reaction? C6H5OH + H2O --- H3O+ + C6H5O-
H3O+
Which one of the following is a conjugate acid-base pair?
HCO3- and CO3 2-
Consider the reversible chemical reaction shown below. What is a base in this reaction? NH3 (aq) + H2O (l) --- NH4+ (aq) + OH- (aq)
NH3
Consider the reversible chemical reaction shown below. What is the conjugate base of NH 4 + in this reaction? NH4++H2O---NH3+H3O+
NH3
Which of the following is likely to behave as a Bronsted base?
NaOH
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
Only solutions A, B, C and D are acidic.
Which of the following materials will react with an acid to produce carbon dioxide?
Sodium bicarbonate (NaHCO3)
Which of the following materials will react with an acid to produce a gas?
Sodium carbonate and sodium bicarbonate
A titration experiment is generally performed to determine which of the following?
The concentration of a particular acid or base
Which of the following is true about an aqueous solution that has a pH equal to 7.
The number of OH- ions is equal to the number of H3O+ ions.
F - is acting like an base in the reaction below. HF+H2O---F_+H3O+
True
H2O is acting as a base in the reaction below: CH3COOH+H2O---CH3OO_+H3O+
True
H3O+ is behaving like an acid in the reaction shown below. NH4++H2O---NH3+H3O+
True
In the generalized shown below, the BH + is acting like an acid: BH++H2O---B+H3O+
True
The chemical equation below correctly shows a neutralization reaction. HCl+LiOH---LiCl+H2O
True
The reaction shown below is an example of a neutralization reaction. HCLO4+LiOH---H2O+LiCLO4
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
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
The hydronium ion concentrations of different solutions are listed below. Which concentration corresponds to the most acidic solution?
[H3O+] =1 x 10^-1
A substance that forms hydroxide ions (OH -) in water and/or accepts protons (H +) is classified as which of the following?
a base
A substance that can behave as either an acid or a base is:
an amphiprotic substance
The difference between a strong and weak acid is that the strong acid ionizes ______, whereas the weak acid ionizes ______. (Fill in the two blanks).
completely; slightly
Carbonic acid _________________. (Fill in the blank)
decomposes to form carbon dioxide gas.
The pH values of different solutions are listed below. Which pH corresponds to the most basic solution?
pH=13