1 Which graph shows activation energy? A Energy vs time B Energy vs reaction progress C Temperature vs time D Pressure vs volume
3 Photosynthesis is an example of: A Exothermic reaction B Endothermic reaction C Neutral reaction D Decomposition
4 Which factor does not affect activation energy? A Catalyst B Nature of reactants C Temperature D Mass of products
8 Which process requires activation energy? A All chemical reactions B Only exothermic reactions C Only endothermic reactions D Only physical changes
9 Heat of reaction depends on: A Path of reaction B Initial and final states C Speed of reaction D Color of reactants
10 Which reaction is safer due to lower activation energy? A Slow reaction B Fast reaction C Explosive reaction D Uncontrolled reaction
12 Which reaction has products with lower energy than reactants? A Endothermic B Physical C Exothermic D Neutral
13 What does ΔH represent? A Change in pressure B Change in temperature C Change in enthalpy D Change in mass
15 Calorimeter is used to measure: A Temperature only B Heat of reaction C Pressure change D Volume change
17 Which reaction absorbs heat from surroundings? A Combustion B Neutralization C Endothermic D Oxidation
19 What is the heat of reaction? A Heat lost by surroundings B Heat gained by system C Heat change during reaction D Temperature change only
20 Burning of fuel is an example of: A Endothermic reaction B Exothermic reaction C Physical change D Neutral reaction
21 Which law explains constant heat change? A Boyle’s law B Hess’s law C Charles’s law D Dalton’s law
22 The energy profile of an endothermic reaction shows: A Products lower than reactants B Products higher than reactants C No energy change D Same energy level
23 Which statement is true for exothermic reactions? A Products have more energy B Reactants have less energy C Energy is absorbed D Energy is released
24 Heat change measured at constant pressure is: A Internal energy B Enthalpy change C Entropy D Activation energy
26 Which reaction has higher activation energy? A Fast reaction B Slow reaction C Catalyzed reaction D Neutral reaction
28 What happens to surroundings in an endothermic reaction? A They gain heat B They lose heat C They gain mass D No change