Enthalpy

What is a state function in thermodynamics?

• A property that depends on the path taken

• A property that depends only on the initial and final states

• A property that changes with temperature

• A property that is always constant

Tags

NGSS.HS-PS3-4

Which of the following is a path function?

• Heat

• Standard enthalpy of formation

• Enthalpy

• Internal energy

Tags

NGSS.HS-PS3-4

Why is enthalpy a practical measure of heat in chemical reactions at constant pressure?

• It includes the work done by expanding gases

• It is always zero

• It does not change with temperature

• It is independent of pressure

What does Hess’s Law state about enthalpy change?

• It is always negative

• It is always positive

• It depends only on the initial and final states

• It depends on the path taken

How do chemical bonds store energy?

• As stored energy

• As sound

• As light

• As heat

Tags

NGSS.HS-PS1-4

What is the role of calorimetry in thermodynamics?

• To measure heat transfer during reactions

• To measure temperature changes

• To measure volume changes

• To measure pressure changes

Tags

NGSS.HS-PS3-4

How does the standard enthalpy of formation help in thermochemical calculations?

• By increasing the complexity of calculations

• By providing a baseline of zero for elements in their most stable forms

• By making all reactions exothermic

• By making all reactions endothermic

What is the significance of understanding exothermic and endothermic reactions?

• To decrease the pressure of reactions

• To increase the temperature of reactions

• To make reactions faster

• To design energy-efficient processes

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

What is the main advantage of using enthalpy in laboratory conditions?

• It simplifies calculations by ignoring pressure

• It directly correlates with heat exchange

• It is always constant

• It does not require temperature measurements

How do thermochemical principles apply to everyday technology?

• By improving the safety and effectiveness of heating devices

• By making devices more expensive

• By reducing the need for energy

• By complicating the design process

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-5

NGSS.HS-PS3-4