definitions
Measure of disorder of a system or molecular randomness
Entropy
What is the most entropic state of matter?
Gas
Which order of reaction directly affects the rate of reaction?
First Order Reaction
At equilibrium what is Delta G equal to?
Find Delat S for the following reaction:
2C2H6(g) + 7O2(g) ----> 4CO2(g) + 6H2O (l)
C2H6 = 229.2 J/mol K
O2 = 205.2 J/mol K
CO2 = 213.8 J/mol K
H2O = 70.0 J/mol K
-619.6 J/mol K
ΔG, ∆S, and ΔH all have the same general equation form...
ΔG, ∆S, ΔH = ∑(products) - ∑(reactants)
True or False.
Temperature is directly proportional to entropy.
True
True or False: The overall reaction rate is always positive.
True
What is the general form for K, for reaction going to products.
K = [products]/[reactants]
Find the change in enthalpy for the following reaction.
P4O6 + 2O2 --> P4H10
using:
P4 + 3O2 ---> P4O6 Hrxn = -16740.1 kJ/mol
P4 + 5O2 ---> P4H10 Hrxn = -2940.1 kJ/mol
13,800 kJ/mol
When the forward and reverse reactions are occurring at the same rate
Equilibrium
Which one of the following processes produces a decrease in the entropy of the system?
A) dissolution of solid KCl in water
B) mixing of two gases into one container
C) freezing water to form ice
D) melting ice to form water
E) boiling water to form steam
C
1st order
What are the units of k for a 2nd order reaction.
M-1s-1
For the first order reaction A ----> products, if the rate of reaction is = 0.00250 M-1 s-1 and [A] = 0.484 M, what is the rate constant K for this reaction?
5.17 x 10-3 s-1
Area of chemistry concerned with the speeds, or rates, at which a chemical reaction occurs
Kinetics
What are the units for entropy?
J/K or Joules pre Kelvin
The concentration of A at 20 seconds is 0.40 M and at 40 seconds is 0.175 M. Calculate the average rate of reaction.
A ---> B
For the following rate law, what is the reaction order?
rate = k[A][B]2
3rd order
rate = k [ClO2]2[OH-]
k = 230 M/s
A perfectly ordered pure crystalline at zero Kelvin will have zero entropy.
Third Law of Thermodynamics
A thermodynamic identity that relates entropy and enthalpy.
Gibbs Free Energy
In the reaction A + 2 B → 3 C + 4 D, the initial concentration of B was 0.0443 M after 17.3 min the concentration of B was 0.0305 M. What is the average rate of disappearance (M/s) of reactant A?
6.65 x 10-6 M/s
For the general reaction, write the rate in terms of C
A + 2B ---> 3C +2D
-1/3 Δ[C]/Δt
Suppose that, at a particular moment during the reaction, CH4 is reacting at the rate of 0.020 M/s. At What rate is CCl4 being formed?
CH4 + 4Cl2 --> CCl4 + 4 HCl
0.020 M/s