Chapter 4 Flashcards
What is a combustion reaction?
Is a particular type of a chemical reaction of hydrogen with oxygen
What is a chemical equation?
A representation of a chemical reaction
What are reactants?
The substances in the left side of the equation
What are products?
The substances on the right side are called products
How do you write a chemical equation?
- Produce a skeletal equation
- Balance atoms in more complex substances first
- Balance free elements
- Check the balance of all atoms
Wha is a solution?
A homogeneous mixture of two substances such as salt and water
What is a solvent?
The major component of a solution, usually the liquid part
What is a solute?
The minority of a solution, most likely the solid part of the solution
What is a solute solvent interaction?
When a solid is put into a solvent, the interactions between solvent and solute particles compete with the interactions among the solute particles themselves
What are electrolytes?
Substances that dissolve in water to form solutions that conduct electricity are electrolytes
A salt solution will conduct electricity (NaCl)
What are strong electrolytes?
Substances such as sodium chloride that completely dissociate into ions when they dissolve in water are strong electrolytes
Ionic compounds form what?
Ionic compounds dissociate in water and can conduct electricity so they form electrolytes in water
What are non-electrolytes?
Compounds such as aura that do not dissociate into ions when dissolved in water are nonelextrolytes and the resulting solutions (non electrolyte solutions) do not conduct electricity
Acids are what?
Acids are molecular compounds but they do ionize and form ions when they dissolve in water
What is a strong acid?
An acid that completely ionizes in solutions
Since they completely ionize, they are strong electrolytes
What is a weak acid?
Acids that do not completely ionize in water
Composed mostly of the nonionized form of the acid molecules
ie.) acetic acid
What are weak electrolytes?
Weak acids are classified as weak electrolytes and the resulting solution (weak electrolyte solutions) conduct electricity only weakly
What does soluble mean?
A compound that dissolves in water
What does insoluble mean?
A compound that does not dissolve in water
What is a chemical reaction?
A process in which one or more substances are converted into one or more different ones
what are the general solubility rules for ionic compounds in water?
- All salts containing cations of group 1 metals (alkali metals, Li+ , Na+ , K+ , etc.) and ammonium ions (NH4 ) are soluble.
- All nitrates (NO3–) , ethanoates (acetates, CH3COO– ), chlorates (ClO3–), and perclorates (ClO4–) are soluble.
- Salts containing Ag+ , Pb2+, and Hg22+ are insoluble
- Most chlorides (Cl–) , bromides (Br–) , and iodides (I–) are soluble.
- Sulfates (SO42–) are soluble, except those containing Ca2+ , Sr2+ , Ba2+
- Carbonates (CO32–) , hydroxides (OH–), oxides (O2–) , phosphates (PO43–) , and sulfides (S2–) are generally insoluble
what is a precipitate reaction?
ones in which a solid or a precipitate forms
what is a precipitate?
a solid, an insoluble ionic compound that forms, separate from the solution
what is a molecular equation?
an equation showing the complete neutral formula for each compound in a reaction
what is a complete ionic equation?
an equation which lists individually all of the ions present as either reactants or products in a chemical reaction
what are spectator ions?
ions in a complete ionic equation that do not participate in the reaction and therefore remain in the solution
what is a net ionic equation?
an equation that shows only the species that change during the reaction
what is an acid-base reaction (neutralization reaction)?
a reaction in which an acid and a base react, neutralizing each other, producing water and a salt
what is the Arrhenius definition of an acid?
substances that produce H+ ions in an aqueous solution
H+ is a bare proton, bare protons associate with water molecules to form hydronium ions
what is the Arrhenius definition of a base?
substances that produce OH- ions in an aqueous solution
what are hydronium ions?
the ion formed from the association of a water molecule with an H+ ion donated by an acid
what is a polyprotic acid?
an acid that contains more than one ionizable proton and releases them sequentially
what is a diprotic acid?
an acid that contains two ionizable protons
what is a gas-evolution reaction?
a reaction in which two aqueous solutions are mixed and a gas forms, resulting in bubbling
what is an oxidation-reduction reaction (redox reaction)?
reactions in which electrons are transferred from one reactant to another and the oxidation states of certain atoms are charged
what does oxidation mean?
the loss of one or more electrons; also the gaining of oxygen or the loss of hydrogen
what does reduction mean?
the gaining of one or more electrons; also the gaining of hydrogen or the loss of oxygen
what is an oxidation state?
a positive or negative, whole number that represents the “change” an atom in a compound would have if all all shared electrons were assigned to the atom with a greater attraction for those electrons
what are the rules for assigning oxidation states?
- The oxidation state of each atom in an element is 0.
- The oxidation state of the atom in a monoatomic ion is equal to the ion’s charge.
- The sum of the oxidation states of all atoms in: A neutral molecule is always zero, a polyatomic ion is always equal to the charge of the ion
- In their compounds, metals have positive oxidation states: Group 1 metals always have an oxidation state of + 1, Group 2 metals always have an oxidation state of + 2
- The oxidation state of hydrogen in a compound is usually + 1
- Nonmetals are assigned oxidation states according to the table on the next slide. Entries at top of table take precedence over those lower down
what are the rules for assigning oxidations states to nonmetals?
a) Fluorine always has an oxidation state of - 1 b)The other group 17 elements usually have an oxidation state of - 1
c) Oxygen usually has an oxidation state of -2
d) The other group 16 elements usually have an oxidation state of - 2
e) Group 15 elements usually have an oxidation number of - 3
what is an oxidizing agent?
a substance that causes the oxidation of another substance
an oxidizing agent gains electrons and is reduced
what is a reducing agent?
a substance that cause the reduction of another substance
a reducing agent losses electrons and is oxidized
what is stoichiometry?
The numerical relationships between reactants and products in a balanced chemical equation
what is a limiting reactant?
the reactants that has the smallest stoichiometric amount in a reactant mixture and consequently limits the amount of product in a chemical reaction
what is a theoretical yield?
The greatest possible amount of product that can be made in a chemical reaction based on the amount of the limiting reactant
what is the formula for percent yield?
% yield = actual yield/ theoretical yield x 100%
what is molarity?
A means of expressing solution concentration as the number of moles of solute per litre of solution
what are stock solutions?
a highly concentrated form of a solution used in laboratories to make less concentrated solutions via dilution
what are concentrate solutions?
a solution that contains a large amount of solute relative to the amount of solvent
what is a diluted solution?
a solution that contains a very small amount of solute relative to the amount of solvent
M1V1 = M2V2
