chem 11

A solution has an initial concentration of weak acid (HA) equal to 2.50M and has a pH of 2.200 at equilibrium. What is the percent ionization of the acid?

.252%

Calculate the molar concentration for H2SO4 in the following situation. When 54ml of it was completely titrated by 25ml of 1.2M NaOH, 1mol of acid was titrated by 2mol of base. Give your answer in two significant figures.

.28

The end point in a titration of a 16ml sample of aqueous HCl was reached by addition of 21.89ml of 0.32M titrant. The titration reaction is HCl+KOH→KCl+H2O What is the molar concentration of HCl? Give your answer in two significant figures.

.44

Choose the Ka value that corresponds to the strongest acid.

0.045

The end point in a titration of a 42ml sample of aqueous (CH3COOH) was reached by addition of 14ml of 0.2M titrant. The titration reaction is CH3COOH+NaOH→CH3COONa+H2O What is the molar concentration of (CH3COOH)?

0.0667 M

The end point in a titration of a 52 ml sample of aqueous CH3COOH was reached by addition of 9.3 mL of 0.75 M titrant. The titration reaction is: CH3COOH+KOH→CH3COOK+H2O What is the molar concentration of CH3COOH?

0.13

The end point in a titration of a 45ml sample of aqueous HCl was reached by addition of 36.27ml of 0.350M titrant. The titration reaction is HCl+KOH→KCl+H2O What is the molar concentration of HCl? Give your answer in three significant figures.

0.282

Calculate the molar concentration for H2SO4 for the following situation. When 27ml of it was completely titrated by 19ml of 0.90M KOH, 1mol of acid was titrated by 2mol of base.

0.32

During the formation of NH4Cl , which of the following is NOT true? 1. The salt NH4Cl is formed by the reaction of the weak base ammonia with the strong acid hydrochloric acid. 2. A solution of NH4Cl contains ammonium ions and chloride ions. 3. The chloride ion does not affect the acidity or basicity of the solution because HCl is a strong acid. 4. The ammonium ion reacts with water to produce a small amount of hydronium ion, making the solution basic.

4

Which of the following Ka values corresponds to the strongest acid?

4.1*10^-3

A solution of nitrous acid, HNO2, is found to have the following concentrations at equilibrium: [HNO2]=0.050M and [H3O+]=[NO−2]=4.8×10−3M What is the Ka of nitrous acid?

4.6×10−4

Calculate the hydronium ion concentration of a solution with a pH of 9.30.

5.0 x 10^-10 M

A solution has an initial concentration of weak acid (HA) equal to 0.150M and has a pH of 1.900 at equilibrium. What is the percent ionization of the acid?

8.39%

Sulfuric acid reacts with sodium carbonate to form water, a salt, and a gas. Write the formulas for the salt and other compound that are formed in the reaction. Na2CO3(aq)+H2SO4(aq)⟶H2O(l)+?+?

CO2 Na2SO4

When hydrofluoric acid (HF), a weak acid, reacts with calcium hydroxide (Ca(OH)2), a strong base, a salt is produced. What is the chemical formula of the salt?

CaF2

What is the active ingredient of the antacid Tums?

Calcium carbonate

Choose the option below that is a base ionization reaction.

H2O+HS−↽−−⇀H2S+OH−

All the following are acid ionization reactions EXCEPT

H2O+HS−↽−−⇀H2S+OH−.

Hydrobromic acid, HBr, is a strong acid, and sodium hydroxide, NaOH, is a strong base. Write the equation for the neutralization reaction between hydrobromic acid and sodium hydroxide. Do not include the designations for the states of matter in your equation. Assume the reaction goes to completion.

HBr + NaOH -> NaBr + H2O

Which acid is the strongest when dissolved in water? Ka values are listed next to the acid.

HClO2, Ka=1.1×10−2

Which among the following best describes the redox reaction where acids oxidize metals to produce hydrogen gas?

It is a single displacement reaction in which an ion in solution is reduced via the oxidation of a metallic element.

Determine the Kb for the base B given that the equilibrium concentrations are [B]=2.6 M, [HB+]=0.143 M, and [OH−]=6.2×10−2 M. Report your answer with 2 significant figures.

Kb=3.4*10^-3

What is the conjugate acid in the forward reaction? NH3+HCN⇌NH4++CN−

NH4+

Which of the following is a product of the reaction of ammonia (NH3) and hydrochloric acid (HCl) in an aqueous solution?

NH4Cl(aq)

What are the products that form as a result of the neutralization reaction of acetic acid (CH3CO2H) and sodium hydroxide (NaOH) in an aqueous solution?

NaCH3CO2 and H2O (ONLY ANSWER)

Consider the reaction described by the following equation. CO2(g)+H2(g)⇌CO(g)+H2O(g) How will the position of the equilibrium change if the volume of a vessel that contains this reaction is decreased?

No change will be observed.

Which of the following do not result from the addition of more reactants to a chemical system at equilibrium? (select all that apply)

Only one of the reactants will be consumed. The value of K increases.

Consider the following chemical equation to answer the question that follows. A+B↽−−⇀C+D An additional amount of reactant A is added to a system at equilibrium. Which of the following will change as equilibrium is reestablished?

The amount of reactant A. The amount of reactant B. The amounts of the products.

Which of the following are results of increasing the temperature of a system that includes an endothermic reaction in the forward direction? (select all that apply)

The concentrations of the products increase. The concentrations of the reactants decrease.

Which of the following are not results of adding a catalyst to a chemical system at equilibrium? (select all that apply)

The reaction quotient decreases. The equilibrium constant increases.

Of the following, which are not results of adding a catalyst to a chemical system at equilibrium? (select all that apply)

The reaction shifts toward the reactants. The reaction quotient increases. The equilibrium constant increases.

Which of the following is true of water in a base ionization reaction? MULTIPLE PICKS BUT THERE'S ONLY 1 ANSWER :)

Water loses a proton and is acting as an acid.

A weak acid will have _______.

a low Ka value

The equation below is an example of which of the following? CH3COOH+H2O↽−−⇀H3O++CH3COO−

acid ionization

If a strong acid and weak base participate in a neutralization reaction, the resulting solution will be __________.

acidic

Which of the following reactions are typically used for titration analyses?

all of the above

Which of the following statement(s) is true about the reactions of baking powder and/or baking soda in the making of baked goods?

all of the above

The substance in a titration with the unknown concentration is called the __________.

analyte

pH is the negative logarithm of the concentration of what molecule/atom?

hydronium

What substance is added to the sample solutions to impart a change in color at or very near the equivalence point of the titration?

indicator

What is the term used to describe the equilibrium constant for the autoionization of water?

ion-product constant.

Based on the following equation, if the concentration of CH3OH(g) doubles, the equilibrium will shift: CO(g)+2H2(g)↽−−⇀CH3OH(g)

left

The reaction of an acid with a base is called a(n) __________ reaction.

neutralization

The hydronium ion concentration of vinegar is approximately 4×10−3 M. What are the corresponding values of pOH and pH?

pH = 2.4, pOH = 11.6

Identify the option below that is a characteristic of acidic solutions

pOH levels greater than 7 at 25∘C

A catalyst will affect a system's

rate of reaction

Identify the name of the solution with the known concentration in titration analyses.

titrant

Identify the method of measuring an unknown concentration by performing a reaction that shows a clearly detectable change when the reactant with unknown concentration is consumed.

titration analysis

A catalyst has no effect on: (select all that apply)

value of an equilibrium constant equilibrium concentrations

Which of the following partially ionizes in solution?

weak base

Strong acids are paired with:

weak conjugate bases

During the formation of sodium acetate, NaCH3CO2 , which of the following is are true? 1. A solution of the salt NaCH3CO2 contains sodium ions and acetate ions. 2. The sodium ion is neither an acid nor a base and thus has no effect on the acidity of the solution. 3. The acetate ion, the conjugate base of acetic acid, reacts with water and increases the concentration of the hydroxide ion. 4. The acetate ion, the conjugate base of acetic acid, reacts with water and decreases the concentration of the hydroxide ion.

1,2,3

Determine the concentration of hydroxide ions for a 25∘C solution with a pH of 8.22.

1.7 X 10^-6M

A solution of ammonia, NH3, is found to have the following concentrations at equilibrium: [NH3]=0.050Mand[NH+4]=[OH−]=9.5×10−4M What is the Kb of ammonia?

1.8*10^-5

The hydroxide concentration of a solution is equal to:

10^-pOH

Calculate the hydronium ion concentration of a solution with a pH of −1.070.

11.7 M

Calculate the pOH of a solution that has [H3O+]=0.050M at 25∘C.

12.70

What will be the pH of a solution with a hydroxide concentration of 4.3×10−2 M?

12.73 or 63

What is the hydronium ion concentration in an aqueous solution with a hydroxide ion concentration of 0.001 M at 25∘C?

1×10−11 M

A solution has an initial concentration of weak acid (HA) equal to 0.150M and has a pH of 1.900 at equilibrium. What is the percent ionization of the acid?

2.6*10^-3

A solution of carbon dioxide in water has a hydroxide ion concentration of 3.5×10−6. What is the concentration of hydronium at 25∘C?

2.9 X 10^-9 M