Chapter 9 Flashcards
A ______ is a process that results in the inter-conversion of chemical substances so that at least one new substance is produced.
chemical reaction
A ______ or _______ is a chemical reaction in which 2 or more reactants are chemically bonded together to form a single product.
synthesis reaction or combination reaction
A ______ is a chemical reaction in which one single reactant is decomposed, or broken down, to produce 2 or more simpler substances.
decomposition reaction
A ________ or _________ is a chemical reaction between an element and a compound in which the element replaces an atom (or group of atoms) from the compound.
single-replacement reaction or
single-displacement reaction
A _______ or a ______ is a chemical reaction in which 2 compounds exchange parts to form 2 new compounds.
double replacement or
double displacement
A ______ is a chemical reaction in which a fuel reacts with an oxidant and produces heat or both heat and light in the form of a glow or flames. Non-scientists would refer to this as burning.
combustion reaction
A ______ is a reaction in which an atom, molecule, or ion gains one (or more) electron(s).
reduction reaction
An _______ is a reaction in which an atom, molecule, or ion loses one (or more) electron(s).
oxidation reaction
The term, _______ is used to describe a chemical reaction where electrons are transferred between reactants.
redox reaction
The term _______ is used to describe a chemical reaction where electron are not transferred between reactants.
nonredox reaction
The pneumonic, “LEO the lion says GER” stands for…
Loss of electrons is oxidation;
gain of electrons is reduction
The pneumonic “OIL RIG” stands for…
Oxidation is loss (of electrons);
Reduction is gain (of electrons)
An “______” called oxidation numbers if used to determine the oxidizing and the reducing species in a redox reaction.
“electron track keeping system”
An ______ is an integer number that represents the charge that a given atom would have if the electrons in each participating bond were assigned to the more electronegative of the two atoms participating in the bond. These are not formal charges on an atom like an ionic charge.
oxidation number
TRUE or FALSE:
Chemical reactions can be classified into a few types.
True
What is the minimum number of new substances that needs to be formed in a chemical reaction?
one
What is the maximum number of new substances that needs to be formed in a chemical reaction?
There is no maximum
TRUE or FALSE:
One of the reactants in a synthesis reaction must be an element.
False
TRUE or FALSE:
The product of a synthesis reaction can never be an element.
True
TRUE or FALSE:
The reactant in a decomposition reaction must be a compound.
True
TRUE or FALSE:
The products of a decomposition reaction could be either elements or compounds.
True
TRUE or FALSE:
The products of a single-replacement reaction are one element and one compound.
True
TRUE or FALSE:
The products of a single-replacement reactions are less complex than the reactants.
False
TRUE or FALSE:
For a combustion reaction to occur, there must always be at least 2 reactants.
True - fuel and oxidant
The species in a redox reaction that lost electrons has been ________.
oxidized
The oxidizing agent in a redox reaction _____ electrons and is itself _______.
gains;
reduced
_______ is a set of statements that describe the necessary conditions that must exist so that a chemical reaction can take place.
Collision theory
What are the 3 central concepts of collision theory?
- Molecular collisions
- Activation energy
- Collision orientation
________ - for a reaction to occur, the reactants must interact with each other. They do so by colliding with each other.
Molecular collision
______ - for a collision to be effective and result in the transformation of reactants to products, the colliding reactants must impact with a minimal amount of energy.
Activation energy
_______ - for a reaction to be successful, the reactants not only need to collide with sufficient energy, they must also collide in the correct orientation.
Collision orientation
Briefly, describe what needs to happen for a chemical reaction to occur.
The reactants need to collide in the proper orientation and with sufficient energy so that existing bonds in the reactant molecules can be broken and new bonds can be formed to make the product molecules.
TRUE or FALSE:
Chemical reactions can only occur in the gaseous or liquid phase.
False
TRUE or FALSE:
Without exception, chemical reactions can occur only if reactant particles collide.
True
The ______, or threshold energy, is the minimum required combined kinetic energy that the colliding particles need to have for a specific chemical reaction to take place.
activation energy
An _______ is a chemical reaction in which energy is released.
exothermic reaction
An _______ is a chemical reaction in which a continuous input of energy is required for the reaction to proceed.
endothermic reaction
TRUE or FALSE:
If the colliding species have kinetic energy that is greater than the activation energy, a chemical reaction will take place.
True - as long as the orientation is favorable
TRUE or FALSE:
Activation energy is a requirement for both endothermic and exothermic reactions.
True
TRUE or FALSE:
An exothermic reaction is a reaction with a low activation energy.
False
TRUE or FALSE:
A successful reaction is more likely to occur when the reacting species are spherical or symmetrical rather than non-spherical or non-symmetrical.
True
A ______ is the rate or speed at which reactants are used up or products are produced.
chemical reaction rate
The study of reaction rates is called ______.
chemical kinetics
Briefly, describe what needs to happen for a chemical reaction rate to increase.
The reaction rate will increase if a reaction factor either lowers the activation energy required or promotes the likelihood of a successful collision.
______ is a way of accelerating the rate of a chemical reaction by providing an alternate reaction route with a lower activation energy.
Catalysis
A _____ is a species that is not consumed in the course of the reaction.
catalyst
TRUE or FALSE:
A catalyst will speed up a chemical reaction until the catalyst is consumed.
False
TRUE or FALSE:
A catalyzed reaction will proceed via a different reaction route but will yield the same final product as a non-catalyzed reaction.
True
Briefly, describe how changing the reactant concentration affects the rate of a chemical reaction.
The rate of a reaction depends on the frequency at which reactant particles (with the correct orientation and energy) collide. Increasing the concentration of reactants will increase the number of particles that can participate in collisions, thus the probability of effective collisions also increases.
Briefly explain why milk will sour in just a couple of days at room temperature, but will remain unspoiled in a refrigerator for 2 weeks.
The rate of the reaction for milk to turn sour is slowed down significantly due to the much lower temperature in the refrigerator. However, no matter how cold the fridge, the milk will eventually spoil!
What two factors determine the physical nature of a reactant?
Its physical state and its particle size
Give 2 options (excluding changing temperature, the concentration, or using catalysts) a chemist has to speed up a reaction that involves a solid.
If possible, dissolve the solid to make it a liquid or decrease the particle size by using a mortar and pestle. You could even use a mortar and pestle first to decrease the particle size and then try to dissolve the powder.
A ________ is a reaction in which the products that are formed can react to produce the original reactants.
reversible chemical reaction
A ________ is a dynamic state in which the forward and the reverse chemical reactions take place at the same time and at the same rate.
chemical equilibrium
What criteria have to be satisfied in order for a chemical reaction to be at equilibrium?
The reaction has to be reversible, and the rate of the forward reaction has to be equal to the rate at which the reverse reaction takes place.
TRUE or FALSE:
The position of the equilibrium depends on whether the reverse or the forward reaction is favored.
False
An _____ is an experimentally determined numerical value that describes a relationship between the concentrations of reactants and products of a system at equilibrium.
equilibrium constant
The _____ is a qualitative indication of the relative amounts of reactants and products present when a chemical reaction reaches equilibrium.
equilibrium position
_____ states that if a chemical system at equilibrium is subjected to a change in conditions (a stress on the system), the system will readjust (change the position of the equilibrium) in the direction that will counteract the imposed stress.
Le Chatelier’s principle
TRUE or FALSE:
The addition of a catalyst puts stress on the reactant side of a reaction and will result in a shift of the equilibrium position to the products side.
False
In an exothermic reaction, ________.
A. heat is needed for a reaction to occur.
B. heat is released as the reaction occurs.
C. heat is a product of the reaction.
D. heat is a catalyst that reduced the activation energy.
E. more than one response is correct.
F. no correct response.
E. more than one response is correct (B and C)
