EXAM - Chemistry II - Chapter 15 - Entropy

it is endothermic, and there is a decrease in disorder.

A process cannot be spontaneous if ___

constant

According to the first law of thermodynamics, the energy of the universe is ___.

sublimation (vaporization) of dry ice, solid CO₂

Based on the relationship of entropy to the degree of disorder in a system, which response represents an increase in entropy?

spontaneous at relatively high temperatures only

Consider the reaction below at 25°C for which ΔS=16.1 J/K. Which one of the following statements describe the reaction?

only below a certain temperature

For the reaction given below, ΔH = -1516 kJ at 25°C and ΔS=-432.8 J/K at 25°C. This reaction is spontaneous....

ΔH is negative, ΔS is positive

In which case must a reaction be spontaneous at all temperatures?

False

T/F: 2H₂ + O₂ -> 2H₂O For the reaction the entropy is increasing.

True

T/F: A spontaneous process is a physical or chemical change that occurs with no outside intervention.

True

T/F: Free energy is the energy that is available to do work for reactions that take place at constant pressure and temperature.

False

T/F: In thermodynamics, the universe is defined as the system minus its surroundings.

False

T/F: Melting ice is an exothermic process and therefore spontaneous.

False

T/F: Rusting is not a spontaneous process.

second

The __ law of thermodynamics states that entropy is always increasing.

energy is conserved during any process

The first law of thermodynamics states that ...

H₂ (g)

The standard Gibbs free energy formation of ___ is zero.

entropy

The thermodynamics quantity that expresses the degree of disorder in a system is __.

freezing water to form ice

Which one of the following processes produces a decrease in the entropy of the system?

dissolving oxygen in water

Which one of the following processes produces a decrease of the entropy of the system?

2NH₄NO₃ -> 2N₂ + 4H₂ + O₂

Which one of the following reactions has a positive entropy change?

when ΔH for a reaction is negative, the reaction is never spontaneous

Which one of the following statements is not correct?

II and IV

Which response contains all the processes below for which ΔS is negative and none for which ΔS is positive?

I and IV

Which responses includes all the following processes that are accompanied by an increase in entropy, and these processes only? I. boiling water II. freezing water III. N₂ + 3H₂ -> @NH₃ IV. Br₂ -> Br₂

2SO₂ + O₂ -> 2SO₃

ΔS is negative for which reaction?