The minimum energy colliding particles must have in order to react
Activation energy
Arrangements of atoms at the peak of an energy barrier
Activated complex
The number of atoms, ions, or molecules that react in a given time to from products
Reaction rate
A substance that interferes with a catalyst
Inhibitor
Energy available to do work
Free energy
When the forward and reverse reactions take place at the same rate
Chemical equilibrium
A reaction that releases free energy
Spontaneous reaction
The measure of disorder
Entropy
Reactants are converted to products In a single step
Elementary reaction
Includes all elementary reactions of a complex reaction
Reaction mechanism
What does a chemical reaction rate measure?
Change in amount of reactant per unit of time
Another name for the activated complex is
Transition state
At what stage of a chemical reaction is chemical energy at its highest level?
When an activated complex exists
Which expression correctly describes activation energy in a chemical reaction?
Energy barrier between reactants and products
Why does a higher temperature causes a reaction to go faster?
Collisions occur more frequently and they occur with greater energy
Why does a higher concentration make a reaction faster?
Higher concentration increases the frequency of collisions
Why does a catalyst cause a reaction to proceed faster?
A catalyst increases the frequency of collisions
What happens to a catalyst during a reaction?
It it unchanged by the reaction
A catalyst works by _______________.
Lowering the activation barrier
Which of the following substances act as a catalyst in the body?
Enzymes
If the reaction is reversible, what are the relative amounts of reactant and product at the end of the reaction?
Some product, some reactant
What happens to a reaction at equilibrium when more reactant is added to the system?
The reaction makes more products
In an endothermic reaction at equilibrium, what is the effect of the rising temperature?
The reaction makes more products
In an equilibrium reaction that makes more moles of gas than it consumes, what is the effect of increasing the pressure?
It makes more reactants
If a reaction has an equilibrium constant just greater than 1, what type of reaction is it?
Reversible, favoring reactants
The energy that is available to do work in a reaction is called_____________.
Free energy
Entropy measures
Disorder
The amount of disorder in a system is measured by its
Entropy
In which of the following systems is the entropy decreasing?
A liquid cooling
When a student in a chemistry lab combines two clear solutions a precipitate forms. What conclusion can the student make about the combined solution?
The product of the concentration of two ions exceeded the Ksp for the compound formed by the ions.
The two factors that determine whether a reaction is spontaneous or non spontaneous are ______________________.
Entropy and enthalpy
Which of the following statements are true?
Entropy always increases In a spontaneous process
Which of the following is always true of a spontaneous reaction?
It releases free energy
Which of the following is true of melting ice at temperatures above 0 degrees Celsius
It is endothermic
Which of the following is true about the combustion of carbon?
...
What determines whether or not a reaction is spontaneous?
Enthalpy change and entropy change
Which of the following is true about numerical value of Gibbs free energy change for a spontaneous reaction?
It is negative
Which if these conditions describes a situation in which a reaction must be nonspontaneous?
Enthalpy decrease and entropy decrease
In a first order reaction, how does the rate change if the concentration of the reaction decreases to one-third its original value?
Third
When nitrous oxide is converted to nitrogen and oxygen, what is the term used to describe the oxygen atoms formed?
Intermediates
Which of the following statements is true of an elementary reaction?
An elementary reaction converts reactants to products in a single step
What is the shape of the graph of energy vs. reaction progress for a complex reaction?
Several hills and valleys
Which of the following requires more information than is provided in a general chemical equation?
The reaction of mechanism ~> all the little reactions taking ace in a big reaction