Entropy and Enthalpy

In a chemistry experiment, Liam, Maya, and Mason are trying to make a reaction happen between two chemicals to create a new compound. What factor can influence the reaction to occur?

• Enthalpy

• Entropy

• Both enthalpy and entropy

• Neither enthalpy nor entropy

Answer explanation

In a chemical reaction, both enthalpy and entropy play significant roles. Enthalpy is the heat content in a system and its change can drive a reaction. Entropy, on the other hand, is a measure of disorder or randomness. A reaction tends to occur if it leads to an increase in entropy. Therefore, both factors can influence the reaction to create a new compound in the chemistry experiment conducted by Liam, Maya, and Mason.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-5

In a science class, Ethan, Isla, and Mason are discussing the concept of entropy. They want to know what entropy measures in the context of determining the entropy of a substance. Can you help them?

• Degree of disorder or randomness

• Pressure of the substance

• Temperature of the substance

• Amount of energy

Answer explanation

Entropy, in the context of science, measures the degree of disorder or randomness in a system. When determining the entropy of a substance, we are essentially quantifying how disordered or random the particles within that substance are. Therefore, the correct answer is 'Degree of disorder or randomness'.

In a chemistry experiment, Noah, Daniel, and Luna are trying to determine the entropy of a substance in a real-world scenario. They are analyzing the melting of ice in a glass of water. What does entropy measure in this context?

• The randomness of a chemical

• The stability of a chemical

• The energy flow in a reaction

• The heat released in a reaction

Answer explanation

In this chemistry experiment, entropy refers to the degree of randomness or disorder in a system. As ice melts in a glass of water, it transitions from a more ordered state (solid) to a less ordered state (liquid), increasing the system's entropy. Therefore, the correct answer is 'The randomness of a chemical'.

Anika, Hannah, and William are helping Zoe in her science lab. They noticed that when Zoe increased the entropy of a system, something happened. What does Zoe observe when she increases the entropy in a real-world scenario like making a cup of hot chocolate?

• The reactions in her experiment start to happen

• The reactions in her experiment stop

• The reactions in her experiment become more stable

• The reactions in her experiment start to release energy

Answer explanation

In a real-world scenario like making a cup of hot chocolate, when Zoe increases the entropy of a system, the reactions in her experiment start to happen. Entropy is a measure of disorder, and an increase in entropy typically leads to a higher likelihood of reactions occurring, as the system becomes more disordered and less stable.

Tags

NGSS.HS-PS3-4

Which of the following scenarios is an example of increasing entropy in everyday life?

• Organizing a bookshelf

• Melting ice cream on a hot day

• Freezing water into ice cubes

• Compressing a gas into a smaller volume

Tags

DOK Level 2: Skill/Concept

Which of the following is an example of entropy decreasing in a system?

• A cup of coffee cooling down

• A room becoming messier over time

• Water freezing into ice

• A car engine running

Tags

DOK Level 2: Skill/Concept

Entropy always increases when

• enthalpy decreases.

• temperature decreases.

• temperature increases.

• volume increases.

Tags

NGSS.HS-PS3-4

Entropy is a measure of

• accuracy

• precision

• the disorder of a system

• the attraction of a nucleus for an electron

Tags

NGSS.HS-PS3-4

In terms of entropy, why is it easier to mix two substances than to separate them once mixed?

• Mixing increases the energy of the system

• Mixing decreases the energy of the system

• Mixing increases the disorder of the system

• Mixing decreases the disorder of the system

Tags

DOK Level 2: Skill/Concept

Which principle states that the total entropy of an isolated system can never decrease over time?

• First Law of Thermodynamics

• Second Law of Thermodynamics

• Third Law of Thermodynamics

• Zeroth Law of Thermodynamics