Understanding Energy and Enthalpy

What is energy primarily responsible for in our universe?

• Creating matter

• Doing work and providing heat

• Forming chemical bonds

• Generating light only

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4

What are the two ways internal energy can be transferred?

• By electricity and magnetism

• By heat and work

• By pressure and volume

• By kinetic and potential energy

Tags

NGSS.HS-PS3-4

What does the concept of 'state function' imply?

• Depends on the path taken

• Only depends on initial and final states

• Is always constant

• Increases with temperature

What is enthalpy represented by?

• A capital E

• A capital H

• A lowercase e

• A lowercase h

Tags

NGSS.HS-PS3-1

What assumption is made for the calculation of enthalpy?

• No work is done by the system

• Temperature is constant

• Pressure is constant

• Volume is constant

What is calorimetry used to measure?

• The color change in reactions

• Temperature changes to determine heat

• Pressure changes in reactions

• Volume changes in reactions

Who is credited with formulating Hess's Law?

• Albert Einstein

• Hermann Hesse

• Marie Curie

• Germain Hess

What does Hess's Law state about enthalpy change?

• It is pathway dependent

• It only depends on the initial and final states

• It changes with pressure

• It is always zero

What is the standard state condition for chemicals in Hess's Law calculations?

• 0 Kelvin and 1 Pascal

• 0 degrees Celsius and 1 atmosphere

• 25 degrees Celsius and 1 atmosphere

• 100 degrees Celsius and 1 bar

How is the enthalpy change for a reaction calculated using Hess's Law?

• Sum of products minus sum of reactants

• Sum of reactants minus sum of products

• Multiplying the reactants by the products

• Dividing the reactants by the products