Thermochemistry Quiz: Energy Changes in Chemical Reactions

In an exothermic reaction, energy is typically transferred in which direction?

• From the surroundings to the system
• From the system to the surroundings
• Energy remains constant
• Energy is completely destroyed

Which of the following best describes an endothermic reaction?

• Releases heat to the surroundings
• Absorbs heat from the surroundings
• Maintains constant temperature
• Produces no energy transfer

The first law of thermodynamics is essentially a statement about:

• Energy can be created from nothing
• Energy can be destroyed completely
• Conservation of energy
• Increasing entropy in all systems

During an exothermic chemical reaction, the temperature of the surroundings will typically:

• Decrease
• Remain constant
• Increase
• Become unpredictable

Which process represents an endothermic reaction?

• Combustion of methane
• Neutralization of an acid and base
• Photosynthesis
• Burning of wood

The first law of thermodynamics can be mathematically expressed as:

• ΔU = Q - W
• ΔU = Q + W
• ΔU = 0
• ΔU = Q × W

In an endothermic reaction, the system's internal energy:

• Decreases
• Increases
• Remains constant
• Becomes zero

Which statement best describes energy transfer in chemical reactions?

• Energy can be created or destroyed
• Energy is always conserved
• Energy only moves in one direction
• Energy transfer is impossible

When heat is absorbed during a reaction, the process is called:

• Exothermic
• Isothermal
• Endothermic
• Adiabatic

The internal energy change (ΔU) represents:

• Total heat added to the system
• Work done by the system
• Change in system's energy state
• Entropy of the reaction