CHAPTER 8- CHEMICAL REACTIVITY

Question 1

What was the main conclusion of the 2002 U.S. Chemical Safety and Hazard Investigation Board (CSB) report on reactive chemical hazards?

Answer 1

B) Reactive chemical incidents are a significant safety problem.

Question 2

What caused the explosion at T2 Laboratories in December 2007?

Answer 2

B) A runaway reaction due to inadequate heat removal from a reactor

Question 3

What is a runaway reaction?

Answer 3

B) A reaction where the temperature rises rapidly due to uncontrolled heat generation

Question 4

According to the CSB’s investigation, why were the engineers at T2 Laboratories unable to prevent the 2007 explosion?

Answer 4

A)They were not trained to recognize reactive chemical hazards.

Question 5

What is the definition of a chemical reactivity hazard?

Answer 5

C) A situation with the potential for an uncontrolled chemical reaction that can cause serious harm

Question 6

What does the acronym CHETAH stand for in the context of predicting reactive chemical hazards?

Answer 6

B) Chemical Thermodynamics and Energy Release Evaluation

Question 7

What happens to the internal temperature of a reactor when there is greater heat loss through the walls?

Answer 7

A) The internal temperature decreases.

Question 8

What is meant by “adiabatic conditions” in the context of reactor behavior?

Answer 8

D) When there is no heat transfer between the reactor and its surroundings

Question 9

Why do larger reactor vessels behave more like adiabatic systems?

Answer 9

B) Because the surface-to-volume ratio decreases, reducing heat loss through the walls

Question 10

What is one major reason scaling up reactions from laboratory size to large commercial reactors can lead to safety incidents?

Answer 10

C) Self-heating rates become significantly higher, leading to uncontrollable temperature rises.

Question 11

What is the primary purpose of a calorimeter in a lab setting?

Answer 11

B) To safely test small amounts of material and study chemical reactions

Question 12

Which company contributed significantly to the development of calorimeter technology in the 1970s?*

Answer 12

B) Dow Chemical

Question 13

What is the main goal of achieving adiabatic conditions in calorimetry?

Answer 13

B) To prevent any heat loss from the system

Question 14

In which calorimeter mode is a sample gradually heated at a constant rate to detect a reaction’s heat?

Answer 14

C) Thermal scan mode

Question 15

Which calorimeter uses a thin-walled glass cell, resulting in low thermal inertia?

Answer 15

D) ARSST

Question 16

Which calorimeter is best suited for studying chemicals with delayed reactions?

Answer 16

A) ARC

Question 17

What is the phi-factor in calorimetry used to represent?

Answer 17

B) The thermal inertia of the calorimeter system

Question 18

What is a characteristic of the DSC (Differential Scanning Calorimeter)?

Answer 18

A) It uses an open system exposed to the atmosphere.

Question 19

Which calorimeter is ideal for testing reactions with very low heating rates?

Answer 19

C) ARC

Question 20

What is indicated by the increase in pressure after a reaction has finished in an APTAC test?

Answer 20

B) Possible decomposition of one of the reaction products

Question 21

How does the heat capacity of the sample vessel affect the accuracy of calorimetric measurements?

Answer 21

C) It ensures that all heat is accounted for in the measurements

Question 22

Which of the following is essential for calculating the heat transferred in a calorimetric experiment?

Answer 22

D) All of the above

Question 23

How is the heat capacity of a calorimeter typically determined?

Answer 23

A) By measuring the temperature change of a known mass of water

Question 24

In a calorimetric experiment, what does a negative value of heat (q) indicate?

Answer 24

B) Exothermic process

Question 25

Why is it important to adjust calorimeter data for the heat capacity of the sample vessel?

Answer 25

A) To ensure accurate measurement of the heat transferred

Question 26

Which equation is used to calculate the heat transferred in a calorimetric experiment?

Answer 26

A) ( q = mc\Δ T )

Question 27

What does the symbol ( ΔT ) represent in calorimetry?

Answer 27

B) Change in temperature

Question 28

If the heat capacity of the sample vessel is not considered, how will it affect the results?

Answer 28

B) The results will be less accurate

Question 29

What is the unit of heat capacity?

Answer 29

B) Joules per degree Celsius

Question 30

What is the specific heat capacity of a substance?

Answer 30

A) The amount of heat required to raise the temperature of 1 gram of the substance by 1°C

Question 31

What type of reaction system where non-condensable gases are produced but the heat of vaporization of the liquid does not always dominate during the entire relief discharge?

Answer 31

B) Hybrid/non-tempered reaction

Question 32

What type of reaction system where non-condensable gases are produced as a result of the reaction?

Answer 32

D) Hybrid/tempered reaction

Question 33

What type of reaction system where tempered reactions are inherently safer since the cooling mechanism is part of the reaction mass?

Answer 33

A) Volatile/tempered reaction

Question 34

The reaction produces non-condensable gases and the liquid is not volatile enough for the heat of vaporization of the liquid to have much effect during the entire relief discharge.

Answer 34

C) Gassy/non-tempered reaction

Question 35

Type of data is used to design and operate processes so that reactive chemical incidents occur.

Answer 35

C) Calorimeter data

Question 36

It can be used to estimate the heat of reaction of the reacting sample.

Answer 36

C) Calorimeter data

Question 37

This analysis provide additional information beyond the kinetic model analysis discussed.

Answer 37

C) Calorimeter analysis

Question 38

This data are then representative of the vapor pressure of the reacting liquid—important data required for relief sizing

Answer 38

D) Pressure data

Question 39

This type of data are most useful for designing relief systems to prevent high pressures due to runaway reactors.

Answer 39

C) Calorimeter analysis

Question 40

In this type of reaction system heat of vaporization of the liquid cools, or tempers, the reaction mass during the relief discharge. This is also called a vapor system.

Answer 40

A) Volatile/tempered reaction