Card Set Information
In Hess's law, what can be done with the reactants and the products?
added and subtracted
When you reverse an equation in Hess' technique, what must happen?
change the sign
Standard heats of formation:
the enthalpy change for the formation of one mole of substance in its standard state from its constituent elements in their standard states
True or False:
The standard heats of formation are per one mole.
the standard heats of formation are per whatever mole we were given in the reaction (the limiting reactant)
What is the standard heat of formation for any element in its standard staet?
In Hess' law and standard heats of formation, the reactants are
In Hess' law and standard heats of formation, the products are:
How can we figure out the standard heat of formation?
Products - reactants
How can bond dissociation energy be used?
to approximate the value for standard heats of formation
How do we solve for H with bond dissociation?
in bond dissociation the reactants are:
In bond dissociation, the reactants are:
What is the second law of thermodynamics:
reactions proceed in the direction that increases the entropy (S) of the system plus surroundings
one that proceeds on its own without any continous external influence
takes place only in the presence of a continuous external influence
The measure of molecular disorder in a system is called the system's __; this is __. What are the units?
Positive value of dS indicates __.
Negative value of dS indicates __.
In terms of both enthalpy and entropy, explain a spontaneous process?
-dH (decrease in enthalpy)
+dS (increase in entropy)
In terms of both enthalpy and entropy, explain a nonspontaneous process?
+dH (increase in enthalpy)
-dS (decrease in entropy)
Which is favored: spontaneous or nonspontaneous?
What is Gibb's Free Energy Change?
weighs the relative contributions of enthalpy and entrophy to the overall spontaneity of a process
When is G spontaneous?
When is dG nonspontaneous?
When is dG at equilibrium?
What does q symbolize?
quantity of heat transferred
The higher the heat capacity (C), what?
the greater the amount of heat needed to produce a given temperature change