Thermochemical Equations and Calculating Enthalpy Changes
This "measurement of internal energy" is roughly the energy held within a compound's chemical bonds.
Enthalpy
This is the total energy available in a system to do work.
What is Gibbs Free Energy?
This order of reaction has a rate that is completely independent of the reactant concentration.
What is Zero Order?
This principle states that a system will shift its equilibrium to avoid stress.
What is Le Chatelier's Principle?
These biological catalysts increase reaction rates without being consumed.
What are Enzymes?
To be considered a true "Thermochemical Equation," a balanced equation must include these two extra pieces of information.
The Physical State (of reactants/products) and the Energy Change
This term refers to the percentage of available energy that is actually used for work.
What is Efficiency?
On a reaction coordinate diagram, this is the highest point—the unstable state between reactants and products.
What is the Transition State?
Increasing the pressure will cause a shift toward the side with fewer of these.
What are Moles of Gas?
Enzymes increase the rate of reaction by lowering this specific "energy hill."
What is Activation Energy?
In an exothermic reaction, like the combustion of methane, you will find the energy value written on this side of the chemical equation.
What is the Product side?
According to the "Law of Disorder," the universe always has a tendency toward this.
What is Entropy/Disorder?
If doubling the concentration of [A] causes the rate to quadruple, [A] is this order.
What is Second order?
If Q is greater than K, the reaction will shift toward this side to reach equilibrium.
What is the Reactant side/Left?
This industrial process involves moving a reaction from a small lab to large-scale production.
What is Reaction Scaling?
GUIDED PRACTICE
Calculate the ΔH of 2LiOH + CO2 --> Li2CO3 + H2O
GUIDED PRACTICE
A reaction has a ΔH of -50 kJ and a ΔS of -0.2 kJ/K. Calculate ΔG at 200 K.
What is -10 kJ?
Work: ΔG = ΔH - (T x ΔS)
ΔG = -50 - (200 x -0.2)
ΔG = -50 - (-40)
ΔG = -10 kJ (Spontaneous)
State the Rate Law formula for a second-order reaction involving reactant (A) and explain what 'k' represents.
Rate = k[A]2
K is the specific rate constant
This biological molecule's binding of CO is essentially irreversible.
What is Hemoglobin?
Using a catalyst in industry allows reactions to occur at a lower ________, saving energy.
What is Temperature?
This is lowest energy phase at 25 degrees C.
What is the standard state?
Enzymes increase reaction rates by providing an alternative pathway with this type of lower energy.
What is activation energy?
This is the slowest step in a multi-step reaction that determines the overall rate.
What is the Rate-Determining Step?
This type of control occurs when reactions are readily reversible and move toward the most stable product.
What is Thermodynamic Control?
Enzymes increase rates not by adding heat, but by providing an alternative what?
What is Reaction Pathway?