Describe Chemical Reactions Flashcards
Chemical Reactions are occurring constantly in nature by:
Creating and breaking bonds between elements and compounds
Chemical Bonds occur when:
Two or more atoms have interactions between electrons
Ionic Bonds can only form when:
The element involved have a large difference in electronegativity, such as exists between metal and nonmetals. The difference allows for the donation of electrons from one element to the other
Ionic Bonds become:
Ions or charged atoms
Metals tend to become:
Positively charged cations
Nonmetals tend to become:
Negatively charged anions
Metals can be found toward the ___ side of the Periodic Table
Left
Nonmetals can be found toward the ___ side of the Periodic Table
Right
Sometimes elements ___ Electrons instead of donating Electrons, forming a different type of bond
Share
Covalent Bonds require:
The sharing of Electrons and occur between two nonmetals
In Covalent Bonds, there is not a ___ ___ in electronegativity to gain or lose Electrons
Sufficient Difference
Differences in Electronegativity within a Covalently Bonded molecule causes them to be:
Polar or Nonpolar
Polar Covalent Compounds have a ___ charged side and a ___ charged side
Negatively, Positively
Water is a ___ Molecule because:
Polar, The Hydrogen side of the molecule is positively charged and the oxygen side is negatively charged as a result of the strong electronegativity of oxygen pulling at the shared electron. These molecules are still neutral in charge
Chemical Reactions are represented by:
Chemical equations
Chemical Equations have a basic pattern:
Reactants, Reaction sign showing the direction of the reaction (–>), and products
What is the formation of Salt in a Chemical Equation?
2Na + Cl2 –> 2NaCl
Chemical Equations must be shown as:
Balanced Equations, meaning there must be the same number of each element on both sides
What are the 5 Basic Chemical Reactions?
Synthesis, Decomposition, Single Replacement, Double Replacement, and Combustion
What is a Synthesis Reaction?
Taking two substances and combining them into a new substance
What is Decomposition?
The opposite of Synthesis, it is a reaction in which a compound is broken down into similar elements that composed the compound
Water can be broken down into:
Hydrogen and Oxygen
Single Replacement is a reaction in which:
An atom or group of atoms is replaced by another
In a Double-Replacement Reaction:
Two replacements happen
What is Combustion? Give an example
Oxygen combines with a compound to form carbon dioxide and water. These reactions give off head and are exothermic. Burning of wood is an example of a Combustion Reaction
Reaction rates can be altered by:
Changing conditions of a reaction
What are examples of Changing Factors?
Pressure, Concentrations of Reactants and Substrates, Temperature, and the Presence of Catalysts
What changes the speed of reactions?
Changing Factors
Changing Factors can be applied to an equation to asses the ___ of ___
Rate, Reaction
Increasing the pressure surrounding a reaction increases the:
Chance of collisions between atoms and molecules and increase the reaction rate
Increasing the Concentration of Reactants increases the probability that:
Reactants will come in contact with each other, thus increasing the likelihood of breaking or creating a bond
If product Concentration is increased, the reaction will:
Slow down
What are Catalysts?
Chemicals that lower the activation energy required for a chemical reaction to occur
What speeds up reactions that would otherwise be extremely slow to occur?
Catalysts
Does the Catalyst change during the reaction?
No
Is the Catalyst reused?
Yes
In Biological Systems, Catalysts are proteins called ___
Enzymes
Examples of Common Ionic Compounds (salts) are:
Sodium Chloride (NaCl) and Potassium Chloride (KCl)
Examples of Common Ionic Compounds are:
Calcium Chloride (CaCl2) and Sodium Bromide (NaBr) and each include a metal and a non-metal
Examples of Common Covalent Bonds are:
Water (H2O), Carbon Dioxide (CO2), and Oxygen (O2)
What is an example of a Common Organic Compound found in Combustion Reactions?
Ethanol (C2H6O)
What’s an example of a Basic Organic Compound?
Glucose (C6H12O6)
pH is a measure of:
The amount of Hydrogen Ions (H+) in a solution
Acids are:
Substances that provide Hydrogen Ions (H+) or accept OJ- ions, and lower pH
Acids have a pH lower than
7
Bases are:
Substances that provide Hydroxide Ions (OH-) or accept H+ ions and raise pH
Bases have a pH higher than
7
Neutral Solutions maintain a pH of:
7
What are great examples of Neutral Solutions?
Water and Human Blood
Cells function in a ___ pH range
Narrow
The human body uses chemicals called ___ to control the pH in the body
Buffers
Buffers can absorb excess:
H+ or OH-
What maintains the proper pH of the body?
Buffers
What are important Buffers in the human body?
Carbon Dioxide and Bicarbonate
