Reactivity 1.4 Flashcards
In terms of spontaniety, describe a process which requires work to be done to make it happen
Non-spontaneous
In terms of spontaniety, describe a process which does not require work to make it happen
Spontaneous
TRUE or FALSE: All exothermic processes are spontaneous
False
TRUE or FALSE: All endothermic processes are non-spontaneous
False
TRUE or FALSE: Spontaneous processes can be exothermic or endothermic
True
TRUE or FALSE: The standard entropy of an element is zero
False
In terms of disorder, describe what happens when entropy is positive
Disorder increases
In terms of disorder, describe what happens when entropy is negative
Disorder decreases
State the units for enthalpy
kJ K⁻¹ mol⁻¹
State the units for entropy
J K⁻¹ mol⁻¹
State the units for gibbs free energy
kJ K⁻¹ mol⁻¹
State the symbol for entropy
S
State the symbol for gibbs free energy
G
State the symbol for enthalpy
H
State the name of the measurement with the symbol H
Enthalpy
State the name of the measurement with the symbol S
Entropy
State the name of the measurement with the symbol G
Gibbs free energy
State the name of the measurement of dispersal of matter and energy in a system
Entropy
What does entropy measure?
The dispersal of matter and energy in a system
Describe how entropy changes if dispersal of matter and energy in a system increases
Entropy increases
Describe how entropy changes if dispersal of matter and energy in a system decreases
Entropy decreases
Describe how the dispersal of matter and energy in a system changes if entropy is positive
The matter and energy becomes more dispersed OR increased amount of disorder
Describe how the dispersal of matter and energy in a system changes if entropy is negative
The matter and energy becomes less dispersed OR decreased amount of disorder
Describe how the entropy of a system changes as temperature increases
Entropy increases
Describe how the entropy of a system changes as temperature decreases
Entropy descreases
Predict the sign of entropy during melting
Positive
Predict the sign of entropy during boiling
Positive
Predict the sign of entropy during condensing
Negative
Predict the sign of entropy during sublimation
Positive
Predict the sign of entropy during vapour deposition
Negative
Predict the sign of entropy during freezing
Negative
Predict the sign of entropy when dissolving a solute to form a solution
Positive
Predict the sign of entropy during precipitation
Negative
Predict the sign of entropy during crystallization from a solution
Negative
Predict the sign of entropy during a chemical reaction when a solid or liquid react to form a gas
Positive
Predict the sign of entropy during a chemical reaction when gases react to form a solid or a liquid
Negative
Predict the sign of entropy during a chemical reaction when there is a increase in the number of moles of gas
Positive
Predict the sign of entropy during a chemical reaction when there is a decrease in the number of moles of gas
Negative
State the value of standard entropy for a perfect crystal of a substance at 0 K
0 J K⁻¹ mol⁻¹
Describe a substance that has a standard entropy of 0
A perfect crystal at 0 K
In terms of spontaneity, describe a reaction that has a positive ΔG value
Non-spontaneous
In terms of spontaneity, describe a reaction that has a negative ΔG value
Spontaneous
In terms of spontaneity, describe a reaction that has a positive ΔH value and positive ΔS value
The reaction will be spontaneous at high temperatures
In terms of spontaneity, describe a reaction that has a positive ΔH value and negative ΔS value
The reaction will be non-spontaneous at all temperatures
In terms of spontaneity, describe a reaction that has a negative ΔH value and positive ΔS value
The reaction will be spontaneous at all temperatures
In terms of spontaneity, describe a reaction that has a negative ΔH value and negative ΔS value
The reaction will be spontaneous at low temperatures
What is the value for ΔG when calculating the temperature at which a reaction becomes spontaneous?
0 kJ K⁻¹ mol⁻¹
When does the value of the reaction quotient equal the value of the equilibrium constant? (Q = K)
ΔGr = 0 OR when the reaction is an equilibrium
What does ΔGr = 0 tell you about a chemical reaction?
It is at equilibrium
What is the value for ΔGr at equilibrium?
0 kJ K⁻¹ mol⁻¹
