Fuels - U3 O1

Question 1

What is the definition of a fuel?

Answer 1

A fuel is a substance that can be burned or consumed to produce energy.

Question 2

True or False: Fossil fuels are derived from ancient organic materials.

Answer 2

True

Question 3

Fill in the blank: Fossil fuels include _____, coal, and natural gas.

Answer 3

oil

Question 4

What is a key characteristic that distinguishes biofuels from fossil fuels?

Answer 4

Biofuels are produced from renewable biological materials, whereas fossil fuels are non-renewable.

Question 5

Multiple Choice: Which of the following is a type of biofuel? A) Coal B) Ethanol C) Natural gas

Answer 5

B) Ethanol

Question 6

What are the two main categories of fuels?

Answer 6

Fossil fuels and biofuels.

Question 7

True or False: Biofuels can be produced from food crops.

Answer 7

True

Question 8

Short Answer: Name one environmental benefit of using biofuels.

Answer 8

Reduced greenhouse gas emissions.

Question 9

Fill in the blank: The process of converting organic matter into biofuels is known as _____ production.

Answer 9

biofuel

Question 10

Multiple Choice: Which of the following is NOT a fossil fuel? A) Petroleum B) Solar energy C) Natural gas

Answer 10

B) Solar energy

Question 12

What is an exothermic reaction?

Answer 12

A reaction that releases energy in the form of heat.

Question 13

What is an endothermic reaction?

Answer 13

A reaction that absorbs energy from its surroundings.

Question 14

True or False: In exothermic reactions, the products have higher energy than the reactants.

Answer 14

False

Question 15

Fill in the blank: In an endothermic reaction, the enthalpy change (ΔH) is __________.

Answer 15

positive

Question 16

Fill in the blank: In an exothermic reaction, the enthalpy change (ΔH) is __________.

Answer 16

negative

Question 17

What occurs during bond breaking in a chemical reaction?

Answer 17

Energy is absorbed to overcome the forces holding the atoms together.

Question 18

What occurs during bond making in a chemical reaction?

Answer 18

Energy is released as new bonds form between atoms.

Question 19

Which type of reaction typically has a decrease in temperature in the surroundings?

Answer 19

Endothermic reaction

Question 20

Which type of reaction typically has an increase in temperature in the surroundings?

Answer 20

Exothermic reaction

Question 21

True or False: All exothermic reactions are spontaneous.

Answer 21

False

Question 22

What is the relationship between bond strength and enthalpy changes in exothermic reactions?

Answer 22

Exothermic reactions typically form stronger bonds in products than those in reactants.

Question 23

What is the key difference in energy changes between exothermic and endothermic reactions?

Answer 23

Exothermic reactions release energy, while endothermic reactions absorb energy.

Question 24

Multiple Choice: Which of the following is an example of an exothermic process? A) Photosynthesis B) Combustion C) Melting ice

Answer 24

B) Combustion

Question 25

Multiple Choice: Which of the following processes is endothermic? A) Dissolving salt in water B) Burning wood C) Respiration

Answer 25

A) Dissolving salt in water

Question 26

What is the unit commonly used to measure enthalpy changes?

Answer 26

Kilojoules per mole (kJ/mol)

Question 27

What is the definition of a fuel?

Answer 27

A substance that provides energy through combustion or chemical reaction. ## Footnote Distinction between fossil fuels (coal, natural gas, petrol) and biofuels (biogas, bioethanol, biodiesel) based on renewability.

Question 28

List the types of fossil fuels.

Answer 28

* Coal * Natural gas * Petrol ## Footnote Fossil fuels are non-renewable resources formed from the remains of ancient organisms.

Question 29

List the types of biofuels.

Answer 29

* Biogas * Bioethanol * Biodiesel ## Footnote Biofuels are renewable resources produced from biological materials.

Question 30

What is renewability?

Answer 30

The ability of a resource to be replaced by natural processes within a relatively short period of time. ## Footnote This concept is critical in distinguishing between fossil fuels and biofuels.

Question 31

What are the fuel sources for the body measured in kJ g-1?

Answer 31

* Carbohydrates * Proteins * Lipids (fats and oils) ## Footnote These macronutrients provide energy for bodily functions.

Question 32

What is photosynthesis?

Answer 32

The process that converts light energy into chemical energy, producing glucose and oxygen. ## Footnote The equation is: 6CO2(g) + 6H2O(l) → C6H12O6(aq) + 6O2(g).

Question 33

What is the balanced equation for cellular respiration?

Answer 33

C6H12O6(aq) + 6O2(g) → 6CO2(g) + 6H2O(l) ## Footnote This process involves the oxidation of glucose as a primary energy source.

Question 34

What is the process for the production of bioethanol?

Answer 34

Fermentation of glucose followed by distillation. ## Footnote The equation is: C6H12O6(aq) → 2C2H5OH(l) + 2CO2(g).

Question 35

What are exothermic reactions?

Answer 35

Reactions that release energy, typically characterized by bond making. ## Footnote They are contrasted with endothermic reactions, which absorb energy.

Question 36

What are endothermic reactions?

Answer 36

Reactions that absorb energy, characterized by bond breaking. ## Footnote Enthalpy changes (∆H) are measured in kJ.

Question 37

What units are used to measure enthalpy changes?

Answer 37

Measured in kJ, molar enthalpy changes in kJ mol-1, and enthalpy changes for mixtures in kJ g-1. ## Footnote These measurements are crucial for understanding energy changes in chemical reactions.

Question 38

What is the significance of energy profile diagrams?

Answer 38

They represent the energy changes during chemical reactions, including activation energy and enthalpy changes. ## Footnote Useful for visualizing exothermic and endothermic reactions.

Question 39

How do you determine limiting reactants in chemical reactions?

Answer 39

By calculating the amount of reactants consumed and identifying which one runs out first. ## Footnote Limiting reactants dictate the maximum amount of product formed.

Question 40

What are combustion reactions?

Answer 40

Exothermic reactions involving the reaction of fuels with oxygen, resulting in the release of energy. ## Footnote Includes complete and incomplete combustion.

Question 41

What is the difference between complete and incomplete combustion?

Answer 41

Complete combustion produces carbon dioxide and water, while incomplete combustion produces carbon monoxide and/or soot. ## Footnote Balanced thermochemical equations are used to represent both types.

Question 42

Fill in the blank: The balanced equation for the complete combustion of organic molecules includes _______.

Answer 42

[Balanced thermochemical equations] ## Footnote These equations include states and are derived from experimental data.