Chapter 16 Chem 2

Which is the correct equation for the calculation of percent ionization of the acid HA in aqueous solution

% ionization = [H+]aq/[HA]0*100%

Which of the following solutions of HCN will have the greatest percent ionization

0.00010M

The [OH-] of a 0.010M Ba(OH)2 solution is - M and the pOH is equal to -

0.020 1.70

Rank the following carboxylic acids in order of increasing acid strength

1. CH3COOH 2. BrCH2COOH 3. ClCH2COOH 4. Cl3CCOOH

Rank these bases in order of increasing strength, placing the strongest base at the bottom of the list

1. Cl3CCOO- 2. Cl2CHCOO- 3. ClCH2COO- 4. CH3COO-

Arrange the following acids in order of greatest to least amount of H3O+ produced in solution at a given concentration

1. HClO2 1.1*10^-2 2. HF 6.8*10^-4 3. HClO 2.9*10^-8 4. HCN 6.2*10^-10

Place the steps required to calculate pH of a 0.10M NaNO2 solution in the correct order

1. Kb for NO2-= (1.0*10^-14)/(4.5*10^-4) = 2.22*10^-11 2. 2.22*10^-11 = [OH-][HNO2]/[NO2] = x2/0.10 3. [OH-]=Sqrt(2.22*10^-11)*0.10 4. pOH=-log(1.49*10^-60=5.82 5. pH = 14.00-5.82=8.17

Rank the sequences of steps you would use to calculate the Kb starting with the pH of a weak base solution of known initial concentration

1. Use pH to calculate POH 2. Calculate [OH-] from pOH 3. Use [OH-] and reaction stoichiometry to calculate equilibrium concentrations of HB+ and B 4. Use the equilibrium expression and calculate the value of Kb

Correctly order the steps necessary to solve weak-acid equilibrium problems starting with the first step at the top of the list

1. Write a balanced equation and Ka expression 2. Define x as the unknown change in concentration that occurs in the reaction and assume x is small compared to [HA] 3. Construct a reaction table that incorporates x and solve for x by substituting values into the Ka expression 4. Check that assumptions are justified using 5% test. If not justified use the quadratic formula to find x

A 0.32M solution of phenol, which is a weak monoprotic acid, has app of 5.22. Place all the steps required to calculate the value of Ka for phenol in the correct order

1. [H3O+] = 10^5.22=6.03*10^-4 2. Assume that [phenol] = 0.32 3. Ka= (6.03*10^-6)^2/(0.32) =1.12*10^-10 4. % ionization = (6.03*10^-6)/(0.32)*100 = 1.87*10^-3% so the assumption is justified

Calculate the [OH-} in a solution that has [H3O+]=6.7*10^-2M is the solution acidic or basic

1.5*10^-13 The solution is acidic

What is the pH of a 0.25M solution of ethanolamine Kb=3.2*10^-5

11.45

Nitrous acid, HNO2, has a Ka of 7.1*10^-4. What is [H3O+] in a .60M solution of HNO2

2.1*10^-2M

Calculate the Ka value for the anilium ion (C6H5NH3+) if Kb for anilium (C6H5NH2) is 4.0*10^-10

2.5*10^-5

When calculating the pH of a weak acid solution it is justified to assume that [H3O+] derived from the acid is negligible when the [H3O+] is less than -% of the initial acid concentration

5

A 0.10M solution of JCN 9Ka=4.9*10^-10) is 7.0*10^-3% ionized. What is the pH of this solution

5.15

When an ionic compound dissociates in water, the separated ions may react with H2O to produce H3O+ or OH- ions. This process known as salt - may affect the - of the salt solution

Hydrolysis pH

Match the relative concentrations of hydronium and hydroxide with the type of solution

Acidic = [H3O+]>[OH-] Basic = [OH-]>[H3O+] Neutral = [H3O+]=[OH=]

Which of the following statements does not describe a type of weak acid

All hydrophilic acids in period 3 or below

The product of a Lewis acid-base reaction is (CH3)2OBF3 Select all the statements that correctly describe this reaction

An empty 2p orbital on B accepts an electron pair from O BF3 accepts an electron pair in this reaction

Which of the following statement correctly describe carboxylic acids, represented by the general formula RCOOH

Carboxylic acids are weaker acids than hydrophilic acids such as HCL Carboxylic acids are organic acids represented by the general formula RCOOH As R changes the strength of the acid changes

Which of the following oxides will not produce a basic solution in water

Cl2O

A salt in which the anion is the conjugate - of a weak - will produce a basic solution

Base Acid

An acid donates a proton to form its conjugate - which therefore has one less - atom and one more - charge than its acid

Base H Negative

Match the following pH values with the type of aqueous solution at 25C

Basic = pH>7.00 Neutral = pH=7.00 Acidic = pH<7.00

Select all the compounds in the following list that are strong bases

Ca(OH)2 NaOH

Select all the weak acids from the following list

CH3CH2COOH HCN HF

Which of the following options correctly describe the structural characteristics of strong and weak bases

Compounds that contain electron-rich N are weak bases Soluble hydroxides are strong bases Amines such as CH3CH2NH2 are weak bases

In an aqueous solution at a given temperature the product [H3O+][OH-] has a - value. This product is equal to - at 25C

Constant 1.0*10^-14

An acid can be defined as a substance that loses one or more H+ ions when dissolved in water. An H+ ion is a hydrogen atom that has lost a(n) - and is therefore just a(n) -. The H+ ion is not an isolated ion, but interacts strongly with H2O to produce the - ion, which has the formula H3O+

Electron Proton Hydronium

A Bronsted-Lowry acid is a proton - and must therefor contain at least ionizable - atom in its formula

Donor Hydrogen

A compound that contains one or more ionizable - atoms as well as one or more available - electron pairs can act as either an acid to a base, depending on the reaction

H Lone

Arrange the following compounds in order of increasing acid strength

H2O HF HBr

The hydrogen phosphate ion, HPO2-4 can act as both a Bronsted acid and Bronsted base in water. Select all the options that correctly describe the reaction that occurs when HPO2-4 acts as a Bronsted base in water

H2O acts as the Bronsted acid OH- is one of the products H2PO-4 is one of the products

Which of the following is not a conjugate acid-base pair

H2PO4- & PO43-

Which statement best explains the trend in acid strength H2SO4>H2SO3>H2SeO3

H2SO4 is stronger than H2SO3 because it has more O atoms

Match each acid correctly to the number of ionizable protons

H3PO4 - 3 H2CO3 - 2 CH3COOH - 1

Which of the following statements correctly explain the relative strengths of the oxyacids shown HBrO<HClO<HClO2<HClO3

HBrO is weaker than HClO because BR is less electronegative than CL HClO3 is stronger than HClO2 because HClO3 has more O atoms

Match each acid with its correct Ka at 25C given that HCN is the weakest and HF is the strongest of the acids listed

HCN = 4.9*10^-10 CH3COOH = 1.8*10^-5 HF = 7.1*10^-4

Which of the following compounds are strong acids

HClO2 H2SO4 HI

Select all the statements that correctly describe the acid-base behavior of H2O

In aqueous HCl water acts as a Bronsted base In aqueous JH3 water acts as a Bronsted acid Water is amphoteric

Oxyacids have the general formula illustrated where the number of bone to the central element E can vary. For the same element E, acid strength will - as the number of O atoms increases. For the same number of O atoms, acid strength increases as the - of the element E increases

Increases Electronegativity

The strength of an acid is measured by its tendency to - and produce - ions in aqueous solution

Ionize Hydrogen

Determine if aqueous solutions of the following salts are acidic, basic, or neutral

KBr - neutral NH4I - acidic KCN - basic

Select all the expressions that correctly express the relationship between Ka and Kb for a conjugate acid-base pair

Ka*Kb=Kw Ka=Kw/Kb

Match each species to the correct Lewis acid-base definition

Lewis base - electron pair donor Lewis acid - electron pair acceptor

Which of the following types of substances are classified as acids only under the Lewis definition

Molecules that contain a polar multiple bond Molecules with electron deficient central atoms

What is the conjugate base of HNO2 if it reacts as a Bronsted acid in H2O

NO-2

Which of the following anions will produce a neutral solution in water?

NO3- I- Cl-

An aqueous NaCl solution was found to have a pH=7.00. Select all the statements that correctly describe this solution

Neither Na+ or Cl- reacts with water The NaCl solution was neutral

An acid-base reaction occurs when one species loses a(n) - and another species simultaneously - a proton. An acid-base reaction can therefore be viewed as a proton- - process

Proton Accepts Transfer

Acid ionization is represented by the general equation HA+H2O(l)=H3O+(aq)+A-(aq) For a strong acid the equilibrium lies far to the - and [H3O+] is much - than [HA]. For a weak acid, on the other hand, the equilibrium lies far to the - and [H3O+] is much - than [HA]

Right Higher Left Lower

Which of the following statements accurately describe Bronsted-Lowry acid-base reactions

Some species can act as either an acid or a base depending on the other species present The reactants and products contain an acid and a base

The two factors that influence the extent of ionizations of an acid are the - and - of the HX bond, where HX is the general formula of an acid

Strength Polarity

The aqueous solutions of a strong acid and a weak acid are compared. Match each acid with the species that is/are present in the greatest concentration in the final solution.

Strong acid: H3O+, A- Weak acid: HA

Which statement most clearly explains the relationship between and acid and its conjugate base

The conjugate base of a weak acid may react with water to a greater extent than the acid itself does

Which of the following statements correctly describe the relationship between a weak acid or base and its conjugate base or acid

The weaker the acid is, the stronger the conjugate base will be The stronger the base is, the more strongly the formation of its conjugate acid is favored

Which of the following options correctly describe the ionization constant Ka?

[H2O] is not included in the Ka expression for a particular acid Ka is the acid ionization constant

A 0.10< NH4Cl solution is found to be acidic. Select the statement that correctly represents the relative [H3O+] and [OH-] in the solution

[OH-]<[H3O+]

Which of the following options correctly describe. solution with a pH = 8.00

[OH-]>[H3O+] The solution is basic

A Bronsted-Lowry base is a proton -. A Bronsted-Lowry base must contain an available - pair of - in its formula in order to form a - bond to H+

acceptor lone electrons covalent

A salt consisting of a small, highly charged metal cation and the anion of a strong acid yields a(n) - solution

acidic

In general, nonmetal oxides tend to be - while mewl oxides tend to be -

acidic basic

The strength of a weak base is indicated by its - ionization constant Kb. The greater the value of Kb the - the base

base stronger

The autoionization of water is a process whereby water ionizes to a small extent to form - ions and - ions

hydronium hydroxide

The quantity -log[H3O+] is called the - of a solution

pH

Calculate the pH and [H3O+] of a 0.080M solution of NaOH

pH = 12.90 [H3O+]=1.3*10^-13M

Place the following pH values in order of increasing [H3O+]. Start with the pH that corresponds to the lowest [H3O+] at the top of the list

pH = 8.5 pH = 7.2 pH = 4.3

Which of the following mathematical relationships are correct for an aqueous solution at 25C

pOH+pH = 14.00 pH = -log[H3O+]