AP Chem 9.2

Give the sign of ΔS for the following: H₂O(g) → H₂O(l)

• Positive

• Negative

• Zero

• Cannot be determined

Give the sign of ΔS for the following: Solid sugar is added to water to form a solution.

• Positive

• Negative

• Zero

• Cannot be determined

Give the sign of ΔS for the following: Sb₄O₆(s) + 6 C(s) → 4 Sb(s) + 6 CO(g)

• Positive

• Negative

• Zero

• Cannot be determined

Give the sign of ΔS for the following: 2 SO₂(g) + O₂(g) → 2 SO₃(g)

• Positive

• Negative

• Zero

• Cannot be determined

What is standard molar entropy?

• The entropy of 1 mol of substance at standard pressure and temperature

• The enthalpy of 1 mol of substance at standard pressure and temperature

• The entropy of 1 mol of substance at any pressure and temperature

• The entropy of 1 mol of substance at 0°C only

Why is it convenient to describe the entropy of a substance in terms of standard molar entropy?

• Because entropy depends on amount, pressure, and temperature

• Because entropy is always constant

• Because entropy does not depend on pressure

• Because entropy is only important for gases

Which of the following statements best explains why the entropy of graphite is higher than that of diamond?

• Graphite is composed of larger atoms

• Graphite has more rigid crystal structure

• Graphite has more disorder due to its softer structure

• Graphite has fewer available microstates

What is meant by "directional bonds" as described in the passage?

• Bonds that allow free rotation of atoms

• Bonds that require a specific orientation of atoms

• Bonds that are weak and flexible

• Bonds that increase molecular motion

Substances with similar ______________ have similar S° values.

• masses

• structures

• colors

• boiling points

Does CH₃CH₂CH₂CH₂OH(l) have a higher or lower S° than CH₃CH₂OH(l)? Explain.

• Higher, because it has a more complex structure.

• Lower, because it has a more complex structure.

• Higher, because it has fewer atoms.

• Lower, because it has fewer atoms.