1 David is studying thermochemistry. He knows that thermochemistry is the study of heat changes in chemical reactions. What is the heat change at constant pressure called? A Internal energy B Enthalpy C Entropy D Free energy
2 Patricia is studying the energy involved in bond breaking and forming. She knows that breaking a bond requires energy and forming a bond releases energy. In an exothermic reaction, which is true? A Energy released in bond formation is greater than energy absorbed in bond breaking B Energy absorbed in bond breaking is greater than energy released in bond formation C Energy released and absorbed are equal D No bonds are broken
3 Hina is studying activation energy. She knows that activation energy is the minimum energy required for a reaction to occur. How does a catalyst affect the activation energy? A Increases activation energy B Decreases activation energy C No effect on activation energy D Increases reaction temperature
4 Waseem is studying endothermic reactions. He knows that some reactions absorb heat from the surroundings. Which of the following is an example of an endothermic reaction? A Combustion of propane B Photosynthesis C Respiration D Rusting of iron
5 Sam is studying the effect of temperature on reaction rate. He knows that increasing temperature increases the rate of reaction. Why does this happen? A Because more molecules have energy greater than activation energy B Because the enthalpy change becomes more negative C Because the catalyst becomes more active D Because the bond dissociation energy decreases
6 Which diagram shows energy changes during a reaction? A Bar diagram B Flow chart C Energy profile diagram D Pie chart
7 Rachel is studying the system and surroundings. She knows that in an endothermic reaction, heat is absorbed from the surroundings. What happens to the temperature of the surroundings? A Increases B Decreases C Remains the same D Fluctuates
9 Which reaction has products with lower energy than reactants? A Endothermic B Physical C Exothermic D Neutral
10 Heat change measured at constant pressure is: A Internal energy B Enthalpy change C Entropy D Activation energy
12 Fatima is studying endothermic reactions. She knows that photosynthesis is an endothermic process. What happens to the enthalpy (ΔH) in an endothermic reaction? A ΔH is negative B ΔH is positive C ΔH is zero D ΔH is undefined
13 Ahmed is studying the enthalpy of reaction. He determines that the reaction A → B has ΔH = +100 kJ. What type of reaction is this? A Exothermic B Endothermic C Thermoneutral D Spontaneous
14 George is studying bond formation and bond dissociation. He knows that energy is released when bonds are formed and energy is absorbed when bonds are broken. What is the term for the energy required to break a bond? A Bond formation energy B Bond dissociation energy C Activation energy D Enthalpy change
15 Nora is studying the energy changes in respiration. She knows that glucose is oxidized to release energy. What is the final electron acceptor in aerobic respiration? A Glucose B Oxygen C Carbon dioxide D Water
16 Uma is studying the role of catalysts in industrial processes. She knows that catalysts are used in the Haber process and contact process. What is the catalyst used in the contact process for making sulfuric acid? A Iron B Vanadium pentoxide C Platinum D Nickel
17 Waseem is studying the energy changes in respiration. He knows that anaerobic respiration produces less ATP than aerobic respiration. How many ATP molecules are produced from one glucose molecule in anaerobic respiration? A 2 ATP B 36 ATP C 4 ATP D 18 ATP
18 Zara is studying anaerobic respiration. She knows that yeast undergoes anaerobic respiration to produce alcohol. What is the product of anaerobic respiration in yeast? A Lactic acid B Ethanol and carbon dioxide C Water and oxygen D Glucose and oxygen
21 Which process requires activation energy? A All chemical reactions B Only exothermic reactions C Only endothermic reactions D Only physical changes
22 Bilal is studying a reaction where the temperature of the solution decreases. He feels the beaker and it becomes cold. Based on this observation, what type of reaction is occurring? A Exothermic B Endothermic C Combustion D Oxidation
24 Which reaction is safer due to lower activation energy? A Slow reaction B Fast reaction C Explosive reaction D Uncontrolled reaction
25 Which reaction has higher activation energy? A Fast reaction B Slow reaction C Catalyzed reaction D Neutral reaction
26 Julia is studying respiration. She knows that aerobic respiration requires oxygen, while anaerobic respiration does not. Which type of respiration produces more energy (ATP)? A Anaerobic respiration B Aerobic respiration C Both produce equal energy D Neither produces energy
27 Tina is studying respiration. She knows that respiration occurs in living organisms to release energy. Which of the following is the correct word equation for aerobic respiration? A Glucose + oxygen → carbon dioxide + water + energy B Glucose → carbon dioxide + ethanol + energy C Glucose + oxygen → carbon dioxide + ethanol D Glucose → lactic acid + energy
28 Oliver is studying the enthalpy of combustion. He knows that the enthalpy of combustion of methane is -890 kJ/mol. What does this indicate? A The reaction absorbs 890 kJ of heat B The reaction releases 890 kJ of heat per mole of methane C The reaction has no heat change D The reaction requires 890 kJ of activation energy
29 What is activation energy? A Energy released B Minimum energy to start a reaction C Energy of products D Energy at room temperature
30 What happens to surroundings in an endothermic reaction? A They gain heat B They lose heat C They gain mass D No change