Entropy

Which of these processes represents a decrease in entropy?

• sublimation of CO₂

• boiling water

• condensation of steam on cold glass

• NaCl dissolving in water

Systems in nature tend to undergo changes toward

• lower energy and less disorder

• lower energy and more disorder

• higher energy and less disorder

• higher energy and more disorder

Tags

NGSS.HS-PS3-4

Entropy increases from solid, liquid to gas. Why?

• Molecular disorder increases
• Molecular randomness decreases
• Molecules are more energetic
• Molecules are more reactive

Which has higher entropy?

A. An enclosed space is filled with ash and smoke particles.

B. A pile of logs sits on the floor of an enclosed space.

• A

• B

Which has higher entropy?

A. Broken pieces of glass lie on a wet floor.

B. A glass of water sits on top of a table.

• A

• B

Which statement is true about the ENTROPY?

• Entropy refers to DISORDER, the unusable energy that escapes a system.
• Entropy refers to the balance of temperature among two or more systems.
• Entropy refers to the average kinetic energy of the molecules.
• Entropy refers to the inability to destroy or create energy. 

Which state of H₂O  has the greatest entropy?

• Ice
• Water
• Vapor

Tags

NGSS.MS-PS1-4

As a system becomes more disordered, entropy

• remains the same
• increases
• decreases
• cannot be determined

Which thermochemical equation is nonspontaneous (based on heat)?

• C₅H₁₂ + O₂ -> CO₂ + H₂O + heat

• Co₂O₃ + heat -> 4 Co + 3 O₂

• Ni + Fe₂O₃ -> Fe + NiO + 938J

• H₂O + SO₃-> 83kJ + H₂SO₄

Tags

NGSS.HS-PS1-4

This reaction is spontaneous because...

2PbSO₄ + heat -> 2PbSO₃ + O₂

• it's endothermic

• it makes smaller molecules (size)

• it makes more stuff/molecules (amount)

• it changes to a liquid

• it makes less stuff/molecules (amount)

Tags

NGSS.HS-PS1-4