Bài tập trắc nghiệm và đáp án môn hóa đại cương Chap 13 14 merged

Bài tập trắc nghiệm và đáp án môn hóa đại cương Chap 13 14 mergedBài tập trắc nghiệm và đáp án môn hóa đại cương Chap 13 14 merged

CHAPTER 14:CONT

The change of concertration with time:

1 Under constant conditions, the half-life of a first-order reaction A) is the time necessary for the reactant concentration to drop to half its original value

B) is constant

C) can be calculated from the reaction rate constant

D) does not depend on the initial reactant concentration

E) All of the above are correct

2 The initial concentration of reactant in a first-order reaction is 0.27 M The rate constant for the reaction is 0.75 s−1 What is the concentration (mol/L)

of reactant after 1.5 s?

A) 3.8

B) 1.7

C) 8.8 × 10−2

D) 2.0×10-2

E) 0.135

3 The rate constant for a second-order reaction is 0.13 M−1 s −1 If the initial concentration of reactant is 0.26mol / L it takes s for the concentration to decrease to 0.13mol / L

A) 0.017

B) 0.50

C) 1.0

D) 30

E) 4.4x10-3

4 The rate constant for this reaction is s − 1

A) 6.9 × 10−2

B) 3.0 ×10− 2

C) 14

D) 0.46

E) 4.0 × 102

5 The concentration of A is M after 40.0 s

A) 1.3 × 10− 2

B) 1.2

C) 0.17

D) 3.5 × 10−4

E) 0.025

6 The rate constant of a first-order process that has a half-life of 225 s is s −1

A) 0.693

B) 3.08x 10− 3

C) 1.25

D) 12.5

E) 4.44x10-3

7 The rate of a reaction depends on

A) collision frequency

B) collision energy

C) collision orientation

D) all of the above

E) none of the above

8 In the Arrhenius equation,

is the frequency factor

A) k

B) A

C) e

D) E a

E) R

9 In general, as temperature goes up, reaction rate

A) goes up if the reaction is exothermic

B) goes up if the reaction is endothermic

C) goes up regardless of whether the reaction is exothermic or endothermic D) stays the same regardless of whether the reaction is exothermic or

endothermic

E) stays the same if the reaction is first order

10 A particular first-order reaction has a rate constant of 1.35 × 102 s −1 at 25.0°C What is the magnitude of k at 95.0 °C if E a = 55.5 kJ/mol?

A) 9.56 × 103

B) 2.85 × 104

C) 576

D) 4.33× 1087

E) 1.36 × 102

CHAPTER 13: PROPERTIES OF SOLUTION

1 The process of solute particles being surrounded by solvent particles is known as

A) salutation

B) agglomeration

C) solvation

D) agglutination

E) dehydration

2 Hydration is a specific example of the phenomenon known generally as

A) salutation

B) disordering

C) solvation

D) condensation

E) dilution

3 Compounds composed of a salt and water combined in definite proportions are known as

A) clathrates

B) homogenates

C) ionic solids

D) molecular solids

E) hydrates

4 An unsaturated solution is one that

A) has no double bonds

B) contains the maximum concentration of solute possible, and is in

equilibrium with undissolved solute

C) has a concentration lower than the solubility

D) contains more dissolved solute than the solubility allows E) contains no

solute

5 A solution with a concentration higher than the solubility is A) is not possible

B) is unsaturated

C) is supercritical

D) is saturated

E) is supersaturated

6 A supersaturated solution

A) is one with more than one solute

B) is one that has been heated

C) is one with a higher concentration than the solubility

D) must be in contact with undissolved solid

E) exists only in theory and cannot actually be prepared

7 In a saturated solution of a salt in water,

A) the rate of crystallization > the rate of dissolution

B) the rate of dissolution > the rate of crystallization

C) seed crystal addition may cause massive crystallization

D) the rate of crystallization = the rate of dissolution

E) addition of more water causes massive crystallization

8 Which one of the following substances would be the most soluble in CCl4 ? A) CH3CH2OH

B) H2O

C) NH3

D) C10H22

E) NaCl

9 Which of the following substances is more likely to dissolve in water? A) HOCH2CH2OH

B) CHCl3

D) CH3(CH2 )8CH2OH

E) CCl4

10 Molality is defined as the

A) moles solute/moles solvent

B) moles solute/Liters solution

C) moles solute/kg solution

D) moles solute/kg solvent

E) none (dimensionless)

11 Of the concentration units below, only is temperature

dependent

A) mass %

B) ppm

C) ppb

D) molarity

E) molality

12 At 20 °C, an aqueous solution that is 24.0% by mass in ammonium chloride has a density of 1.0674 g/mL What is the molarity of ammonium chloride in the solution? The formula weight of NH4 Cl is 53.50 g/mol

A) 5.90

B) 0.479

C) 4.79

D) 0.0445

E) 22.5

13 At 20 °C, a 0.376 M aqueous solution of ammonium chloride has a density

of 1.0045 g/mL What is the mass % of ammonium chloride in the solution? The formula weight of NH4 Cl is 53.50 g/mol

A) 0.381

B) 0.705

C) 0.374

D) 2.68

E) 2.00

14 A solution is prepared by dissolving 16.2 g of benzene (C6H6 ) in 282 g of carbon tetrachloride (CCl 4 ) The concentration of benzene in this solution

is molal The molar masses of C6H6 and CCl 4 are 78.1 g/mol and 154 g/mol, respectively

A) 7.36 × 10−4

B) 0.736

C) 0.102

D) 0.0543

E) 5.43

15 At 20 °C, a 2.32 M aqueous solution of ammonium chloride has a density of 1.0344 g/mL What is the molality of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g/mol

A) 2.55

B) 0.0449

C) 2.32

D) 0.446

E) 12.00

CHAPTER 14:CONT

The change of concertration with time:

1 Under constant conditions, the half-life of a first-order reaction A) is the time necessary for the reactant concentration to drop to half its original value

B) is constant

C) can be calculated from the reaction rate constant

D) does not depend on the initial reactant concentration

E) All of the above are correct

2 The initial concentration of reactant in a first-order reaction is 0.27 M The rate constant for the reaction is 0.75 s−1 What is the concentration (mol/L)

of reactant after 1.5 s?

A) 3.8

B) 1.7

C) 8.8 × 10−2

D) 2.0×10-2

E) 0.135

3 The rate constant for a second-order reaction is 0.13 M−1 s −1 If the initial concentration of reactant is 0.26mol / L it takes s for the concentration to decrease to 0.13mol / L

A) 0.017

B) 0.50

C) 1.0

D) 30

E) 4.4x10-3

4 The rate constant for this reaction is s − 1

A) 6.9 × 10−2

B) 3.0 ×10− 2

C) 14

D) 0.46

E) 4.0 × 102

5 The concentration of A is M after 40.0 s

A) 1.3 × 10− 2

B) 1.2

C) 0.17

D) 3.5 × 10−4

E) 0.025

6 The rate constant of a first-order process that has a half-life of 225 s is s −1

A) 0.693

B) 3.08x 10− 3

C) 1.25

D) 12.5

E) 4.44x10-3

7 The rate of a reaction depends on

A) collision frequency

B) collision energy

C) collision orientation

D) all of the above

E) none of the above

8 In the Arrhenius equation,

is the frequency factor

A) k

B) A

C) e

D) E a

E) R

9 In general, as temperature goes up, reaction rate

A) goes up if the reaction is exothermic

B) goes up if the reaction is endothermic

C) goes up regardless of whether the reaction is exothermic or endothermic D) stays the same regardless of whether the reaction is exothermic or

endothermic

E) stays the same if the reaction is first order

10 A particular first-order reaction has a rate constant of 1.35 × 102 s −1 at 25.0°C What is the magnitude of k at 95.0 °C if E a = 55.5 kJ/mol?

A) 9.56 × 103

B) 2.85 × 104

C) 576

D) 4.33× 1087

E) 1.36 × 102

CHAPTER 13: PROPERTIES OF SOLUTION

1 The process of solute particles being surrounded by solvent particles is known as

A) salutation

B) agglomeration

C) solvation

D) agglutination

E) dehydration

2 Hydration is a specific example of the phenomenon known generally as

A) salutation

B) disordering

C) solvation

D) condensation

E) dilution

3 Compounds composed of a salt and water combined in definite proportions are known as

A) clathrates

B) homogenates

C) ionic solids

D) molecular solids

E) hydrates

4 An unsaturated solution is one that

A) has no double bonds

B) contains the maximum concentration of solute possible, and is in

equilibrium with undissolved solute

C) has a concentration lower than the solubility

D) contains more dissolved solute than the solubility allows E) contains no

solute

5 A solution with a concentration higher than the solubility is A) is not possible

B) is unsaturated

C) is supercritical

D) is saturated

E) is supersaturated

6 A supersaturated solution

A) is one with more than one solute

B) is one that has been heated

C) is one with a higher concentration than the solubility

D) must be in contact with undissolved solid

E) exists only in theory and cannot actually be prepared

7 In a saturated solution of a salt in water,

A) the rate of crystallization > the rate of dissolution

B) the rate of dissolution > the rate of crystallization

C) seed crystal addition may cause massive crystallization

D) the rate of crystallization = the rate of dissolution

E) addition of more water causes massive crystallization

8 Which one of the following substances would be the most soluble in CCl4 ? A) CH3CH2OH

B) H2O

C) NH3

D) C10H22

E) NaCl

9 Which of the following substances is more likely to dissolve in water? A) HOCH2CH2OH

B) CHCl3

D) CH3(CH2 )8CH2OH

E) CCl4

10 Molality is defined as the

A) moles solute/moles solvent

B) moles solute/Liters solution

C) moles solute/kg solution

D) moles solute/kg solvent

E) none (dimensionless)

11 Of the concentration units below, only is temperature

dependent

A) mass %

B) ppm

C) ppb

D) molarity

E) molality

12 At 20 °C, an aqueous solution that is 24.0% by mass in ammonium chloride has a density of 1.0674 g/mL What is the molarity of ammonium chloride in the solution? The formula weight of NH4 Cl is 53.50 g/mol

A) 5.90

B) 0.479

C) 4.79

D) 0.0445

E) 22.5

13 At 20 °C, a 0.376 M aqueous solution of ammonium chloride has a density

of 1.0045 g/mL What is the mass % of ammonium chloride in the solution? The formula weight of NH4 Cl is 53.50 g/mol

A) 0.381

B) 0.705

C) 0.374

D) 2.68

E) 2.00

14 A solution is prepared by dissolving 16.2 g of benzene (C6H6 ) in 282 g of carbon tetrachloride (CCl 4 ) The concentration of benzene in this solution

is molal The molar masses of C6H6 and CCl 4 are 78.1 g/mol and 154 g/mol, respectively

A) 7.36 × 10−4

B) 0.736

C) 0.102

D) 0.0543

E) 5.43

15 At 20 °C, a 2.32 M aqueous solution of ammonium chloride has a density of 1.0344 g/mL What is the molality of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g/mol

A) 2.55

B) 0.0449

C) 2.32

D) 0.446

E) 12.00