Entropy Concepts in Thermodynamics

The video tutorial explains the concept of entropy, starting with its measurement on an absolute scale and the third law of thermodynamics. It discusses how temperature affects entropy, using Boltzmann's equation to relate entropy to microstates. The tutorial defines standard entropy and compares the entropies of different states and substances, highlighting that gases generally have higher entropy than liquids and solids. It concludes with a calculation of entropy change in a chemical reaction, emphasizing the increase in entropy when a solid decomposes into a solid and a gas.

What is the entropy of a pure crystalline substance at absolute zero according to the third law of thermodynamics?

• Zero

• Infinite

• One

• Negative

How does the entropy of a substance change as the temperature increases?

• It becomes zero

• It increases

• It remains constant

• It decreases

What is the standard molar entropy of graphite at 25 degrees Celsius?

• 5.7 joules per kelvin mole

• 0 joules per kelvin mole

• 69.9 joules per kelvin mole

• 186.3 joules per kelvin mole

Which state of matter generally has the highest standard molar entropy?

• Solids

• Liquids

• Gases

• Plasmas

Why do gases generally have higher entropy than solids?

• Gases have fewer particles

• Gases have more microstates due to increased freedom of movement

• Gases are denser

• Gases have stronger intermolecular forces

What is the standard molar entropy of methane gas?

• 5.7 joules per kelvin mole

• 229.6 joules per kelvin mole

• 186.3 joules per kelvin mole

• 69.9 joules per kelvin mole

In the decomposition of calcium carbonate, what is the sign of the standard change in entropy?

• Positive

• Negative

• Zero

• Undefined

What is the standard change in entropy for the decomposition of one mole of calcium carbonate?

• 92.9 joules per kelvin

• 160.5 joules per kelvin

• 39.8 joules per kelvin

• 213.6 joules per kelvin

How does the number of moles of gas on the product side affect the entropy change in a reaction?

• It makes the entropy zero

• It increases the entropy

• It has no effect

• It decreases the entropy

If the decomposition of two moles of calcium carbonate is considered, how would the change in entropy compare to one mole?

• It would be double

• It would be zero

• It would be the same

• It would be half