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57 Cards in this Set

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When a reaction is spontaneous at a high T only, ∆H is ___, ∆S is ______.

When a reaction is spontaneous at high T only, ∆H is positive, and ∆S is positive as well.

When a reaction is never spontaneous, ∆H is _____, ∆S is _______

When a reaction is never spontaneous, ∆H is positive, while ∆S is negative.

When a reaction is spontaneous at all T, ∆H is _____, ∆S is ________.

When a reaction is spontaneous at all T, ∆H is negative, while ∆S is positive.

When a reaction is spontaneous only at low T, ∆H is ______, ∆S is _______.

When a reaction is spontaneous only at low T, ∆H is negative, and ∆S is negative as well.

At low temperatures, reactions are spontaneous (∆G < 0) only if they are (endothermic, exothermic)

At low temperatures, reactions are spontaneous (∆G < 0) only if they are exothermic.

At high temperatures, reactions are spontaneous (∆G < 0) only if they (increase, decrease) entropy.

At high temperatures, reactions are spontaneous (∆G < 0) only if they increase in entropy.

Elements in their standard state are defined to have a standard free energy of formation (∆G) of what?

Elements in their standard state have ∆G = 0.

What is the formula for work? (Both regular and for gases?

w = -P∆V or -∆nRT

Express change in energy formulas

∆E = E[products] - E[reactants]

Relationship between gases and work

We only see energy changes due to work when gases are involved.




Reactions involving gases often result in an increase or decrease in volume.




For a gas to expand, it has to push out.


Force needs to be applied to expand volume.

Endothermic Reaction

Heat transfer to the system from surroundings


∆EN > 0


Work being done on the system


Bonds being made

Exothermic Reaction

Heat transfer from the system to the surroundings


∆EN < 0


Energy lost by system


Bonds being broken

Spontaneous only at high temperatures


∆H =?


∆S = ?

For reactions spontaneous only at high temperatures, ∆H and ∆S are positive

Never spontaneous


∆H = ?


∆S = ?

For reactions that are never spontaneous, ∆H is positive, and ∆S is negative

For reactions spontaneous at all temperatures,


∆H = ?


∆S = ?

For reactions spontaneous at all temperatures, ∆H is negative, and ∆S is positive



For reactions spontaneous at low temperatures only,


∆H = ?


∆S = ?

For reactions spontaneous at low temperatures ∆H is negative, and ∆S is negative.

When gases form from solids or liquids (all the reactants are solids, liquids, or solutions, and at least one product is a gas) change in entropy is (positive, negative)

When gases form from solids or liquids, change in entropy is positive

Entropy (increases, decreases) when mixtures are formed from pure substances

Entropy rises when mixtures are formed from pure substances



Entropy (increases, decreases) when the moles of gases increases

Entropy increases when moles of gases increases

Weak IMF


(Vapor Pressure, surface tension, viscosity, evaporation rate, phase change temperature)

Weak Intermolecular Forces:


Higher Vapor Pressure


Lower Surface Tension


Lower Viscosity


Faster Evaporation Rate


Lower Phase Change Temperature

Strong IMF


(vapor pressure, surface tension, viscosity, evaporation rate, phase change temperature)

Strong Intermolecular Forces:


Lower Vapor Pressure


Higher Surface Tension


Higher Viscosity


Slower Evaporation Rate


Higher Phase Change Temperature

You are told that the enthalpy of the gas mixture goes up, which means that heat was (absorbed, released) during the reaction and the reaction is (endothermic, exothermic)

When enthalpy of a gas mixture goes up, heat is absorbed during the reaction and the reaction is endothermic.

Entropy (increases, decreases) when pure substances are mixed, as long as temperature and volume stay constant.

Entropy increases when pure substances are mixed, as long as temperature and volume stay constant.



Heat flow is considered (positive, negative) when heat flows into a system

Positive

Heat flow is considered (+, -) when work is done on a system

Heat flow is considered positive when work is done on a system

If a real gas has a volume that is larger thanyou would predict based on the ideal gas law,then the intermolecular forces for that gas aredominated by

Repulsive Forces


If the volume of the real gas is larger thanyou would predict based on the ideal gas law,then the compression factor Z > 1. Thismeans the intermolecular forces are dominatedby repulsions between the gas particles(atoms or molecules).

When gas pressure increases, ∆S (+, -)

When gas pressure increases, ∆S < 0

When you increase moles of gas, ∆S (+, -)

When you increase moles of gas, ∆S > 0

When you decrease moles of gas, ∆S (+, -)

When you decrease moles of gas, ∆S < 0

If you have an endothermic process in which the change in entropy is positive, you can make it spontaneous by increasing ______________

Temperature

∆H > 0 for (endothermic, exothermic) processes

Endothermic

If ∆G is negative and T is very large, increasing the temperature makes the process (endothermic, exothermic)

Endothermic

Nitrate

NO3(-)

Nitrite

NO2(-)

Chromate

CrO4(2-)

Dichromate

Cr2O7(2-)

Cyanide

CN(-)

Hydroxide

OH(-)

Carbonate

CO3(2-)

Sulfate

SO4(2-)

Sulfite

SO3(2-)

Oxalate

C2O4(2-)

Phosphate

PO4(3-)

Phosphite

PO3(3-)

Perchlorate

ClO4(-)

Chlorate

ClO3(-)

Chlorite

ClO2(-)

Hypochlorite

ClO(-)

Permanganate

MnO4(-)

Peroxide

O2(2-)

Hydrogen Carbonate

HCO3(-)

Hydrogen Sulfate

HSO4(-)

Hydrogen Sulfite

HSO3(-)

Hydrogen Oxalate

HC2O4(-)

Hydrogen Phosphate

HPO4(2-)

Dihydrogen Phosphate

H2PO4(-)

Hydrogen Sulfide

HS(-)