41. The heat required to raise the temperature of 1 gram of water by 1°C is called:

• A) Specific heat
• B) Heat of formation
• C) Calorific value
• D) Heat of combustion
• Answer: A

42. A reaction that absorbs heat from the surroundings is termed:

• A) Exothermic
• B) Endothermic
• C) Isothermal
• D) Adiabatic
• Answer: B

43. Which of the following would be an example of an exothermic process?

• A) Melting ice
• B) Boiling water
• C) Freezing water
• D) Evaporating alcohol
• Answer: C

44. Which term refers to the amount of heat needed to break a chemical bond?

• A) Bond dissociation energy
• B) Heat of formation
• C) Lattice energy
• D) Heat of vaporization
• Answer: A

45. **The enthalpy change for the reaction A + B → C + D is -200 kJ. This means the reaction is

:**

• A) Endothermic
• B) Exothermic
• C) Neutral
• D) Reversible
• Answer: B

46. When a gas condenses into a liquid, the process is:

• A) Endothermic
• B) Exothermic
• C) Isothermal
• D) Adiabatic
• Answer: B

47. The heat required to break 1 mole of bonds in a substance is called:

• A) Bond energy
• B) Heat of fusion
• C) Heat of reaction
• D) Activation energy
• Answer: A

48. In a chemical reaction, heat is a form of:

• A) Potential energy
• B) Kinetic energy
• C) Thermal energy
• D) Light energy
• Answer: C

49. Which statement best describes an exothermic reaction?

• A) Heat is absorbed from the surroundings
• B) Heat is released to the surroundings
• C) The products have more energy than the reactants
• D) No heat is involved
• Answer: B

50. The heat of reaction for a combustion process is typically:

• A) Positive
• B) Negative
• C) Zero
• D) Unaffected by temperature
• Answer: B