chapter 4 Flashcards
a solution…
is made of a smaller quantity of one substance (solute) dissolved in a larger quantity of another substance (solvent)
What is a solvent?
The substance in a solution that is in the solution that does dissolving (usually water)
What is a solute?
The substance that gets disolved
What is an aqueous solution?
Solutions in which water is the solvent
what is concentration?
The quantity of solute present in a given quantity of soln.
what is the formula for concentration?
Molarity= number of moles of solute (n)/ volume of solution in L (V)
what is the dilution formula?
C1V1=C2V2
what type of displacement reaction are preciptitation reactions?
Double displacement reaction
What is the general formula of precipitation reactions?
AB + CD = AD + CB
when do precipitation reactions occur?
When two ionic compounds are dissolved in water
What do precipitation reactions form?
a new insoluble (or nearly insoluble solid)
what is the solid that falls out of a solution called?
the precipitate
Define molecular equation
It shows all reactants and products as if they were intact, dissociated compounds (including states of matter)
what’s an example of a molecular equation ?
NaCl (aq) + AgNo3 (aq) = NaNO3 (aq) + AgCl (s)
Define total iconic equation
Shows ALL soluble ionic substances dissociated into ions
What is an example of total ionic equation?
Na + (aq) + Cl- (aq) + Ag+ (aq) + NO3- (aq) = Na + (aq) + NO3- (aq) + AgCl (s)
what stays together in total ionic equations?
The precipitate (solids) and compounds ?
Define spectator ions
Appear on both sides of the arrow. They are ions that are not involved in the chemical reaction making the precipitate.
what are the spectator ions in ; Na + (aq) + Cl- (aq) + Ag+ (aq) + NO3- (aq) = Na + (aq) + NO3- (aq) + AgCl (s)
Na and NO3
Define net ionic equations
Equations that focus on the reaction that generates the solid (precipitate). They do not include spectator ions.
How can you predict if a precipitate will form?
- switch ionic partners of reactants (always pair + with- )
2.Fix formulas for new products - Use solubility rules to decide if a product is insoluable
What is an acid?
Produces H+ ions (protons) when dissolved in water.
What is a base?
Produces OH- (hydroxide) ions when dissolved in water
What is the format for acid-base reactions?
acid + base = salt + water
Acid- Base reactions form…
salt and water
H+ does not exists as H+ long in water so it forms H3O
True
Strong acids…
dissociate completely into ions in aqueous solution and they are strong electrolytes
Weak acids…
Dissociate a little in aqueous solutions and are weak electrolytes.
strong base…
dissociate completely into ions in aqueous solutions
weak bases
dissociate very little into ions in aqueous solution
What is an example of an acid base reaction?
HCl + NaOH = NaCl + H2O
define the equivalence point
the point where t he mol of H= from acid equals the mol of OH from the base
Define the end point
it occurs when there is a slight excess of base and the indicator changes color permenently
What happens an a redox reaction?
Electrons are transferred, one element is oxidized another is reduced
Define oxidation
An electron is lost
Define reduction
An electron is gained
Define reducing agent
The element that is oxidized is the reducing agent
Define the oxidation agent
the element that is reduced.
what is the oxidation number for atoms in their elemental form?
0
what is the general format of combination reactions?
X+Y= Z
What is the general format decomposition reactions?
Z= X+Y
What is the general formal of single displacement reactions?
X+YZ = XZ+Y
what are combustion reactions?
It is a redox reaction that normally combines oxygen to release heat
What is the general format of a combustion reaction?
Compound + Oxygen = Carbon Dioxide+ water
forward and reverse reactions happen…
at the same time
