Definitions
Laws
Enthalpy
Entropy
Hess
100
The energy change that accompanies a chemical reaction.
What is a change in enthalpy (ΔH)?
100
Energy cannot be created or destroyed, only change form.
What is the First Law of Thermodynamics?
100
ΔH° is _____________ for endothermic reactions.
What is positive?
100
The entropy of a system __________ with increasing temperature.
What is increases?
100
The enthalpy of any element in its elemental form.
What is 0?
200
The ΔH of a formation reaction
What is Enthalpy of formation (ΔHf)?
200
The entropy of the universe must always either increase or remain the same. It can never decrease.
What is the second law of thermodynamics?
200
ΔH° is _____________ for exothermic reactions.
What is negative?
200
The amount of entropy associated with each state of matter, from lowest to highest.
What is solid, liquid, gaseous?
200
Standard conditions.
What is room temperature (25°C) and normal atmospheric pressure (1.00 atm)?
300
Activation energy
What is the energy necessary to start a chemical reaction?
300
Hess's law.
What is Enthalpy is a state function?
300
Equation for ΔH. (equation 13.2)
What ΔH = Energy required to break bonds - Energy released when bonds form?
300
True or false: ΔS universe ≤ 0
What is false?
300
The standard enthalpy of formation of an element in its elemental form.
What is 0?
400
A measure of the disorder that exists in any system.
What is entropy?
400
ΔH° = ƩΔHf° (products) - ƩΔHf° (reactants) (equation 13.3)
What is Hess's law?
400
If a chemical reaction has a positive ΔH, will the beaker that contains the reaction feel hot or cold once the reaction is finished?
What is cold? (endothermic reaction)
400
Equation for ΔS.
What is ΔS° = ƩS° (products) - ƩS° (reactants)? (equation 13.5)
400
Which substances have a ΔHf° of 0? NaOH (aq), Na+ (aq), O2 (g), O (g), Cl2 (g), H2 (l)
What is O2 (g) and Cl2 (g)?
500
Any quantity that depends solely on the final destination, not on the way we get to that destination.
What is a state function?
500
In a complete combustion, you burn gaseous butane (C4H10). What is the ΔH° for this reaction? (use Hess's law)
What is -5.320 x 10(3) kJ?
500
The ΔH of the following reaction: 2Cl(2) + 2H2O yields 4HCL + O2
What is ΔH = 110 kJ?
500
What is the sign of ΔS for: NH4Cl (s) + H2O (l) yields HCl (g) + NH4OH (g)
What is ΔS is positive?
500
What is the ΔS° of the following reaction? H20 (l) + CaO (s) yields Ca(OH)2 (s)
What is -32.0 J/K?
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