Understanding Entropy and the Second Law of Thermodynamics

What does the Second Law of Thermodynamics state about disorder?

• It decreases over time

• It is not related to thermodynamics

• It remains constant

• It increases in spontaneous processes

Tags

NGSS.HS-PS3-4

What is entropy a measure of?

• Energy efficiency

• Chemical reaction speed

• Molecular randomness or disorder

• Temperature stability

Tags

NGSS.HS-PS3-4

What role does entropy play in chemical reactions?

• It prevents reactions from occurring

• It decreases the energy of reactions

• It stabilizes reaction temperatures

• It helps predict the amount of useful work from a reaction

What does 'spontaneous' mean in the context of chemical reactions?

• The reaction does not need outside energy to proceed

• The reaction requires external energy

• The reaction cannot occur in nature

• The reaction occurs quickly

How can the change in entropy during a reaction be calculated?

• By subtracting reactant values from product values

• Entropy cannot be calculated

• By direct observation

• By measuring the temperature change

Why are most solids not reactive in solid form?

• Due to high entropy

• Because they require aqueous solutions

• Solids are always reactive

• Because of their stable molecular structure

Tags

NGSS.HS-PS1-3

What is Gibbs free energy?

• A constant value for all reactions

• The total energy absorbed by a reaction

• A measure of reaction speed

• Energy available to do useful work

What indicates a reaction is entropy-driven according to Gibbs' criteria?

• The reaction temperature is constant

• "T Delta S" is less than "Delta H"

• "T Delta S" is greater than "Delta H"

• "Delta H" is zero

How does the Gibbs formula help predict spontaneous reactions?

• By observing the reaction

• By the color change in the reaction

• By calculating the change in free energy

• By measuring temperature only

Tags

NGSS.HS-PS3-1

What does a negative Gibbs free energy value indicate about a reaction?

• It is spontaneous

• It is non-spontaneous

• It requires external energy

• It is endothermic