chapter 6: Types of chemical reactions Flashcards
what is dissolution
When an ionic substance dissolves in water, the solvent pulls the individual ions from the crystal and solvates them
What is another name for dissolution?
dissociation
Why is an ionic salt soluble in water?
Because the interactions between ions and water are strong enough to overcome the lattice energy of the crystal
What does (aq) stand for
Aqueous solution
What does aqueous solution indicate
Hydration of the ions
Example of aqueous solution
NaCl —> (H2O) Na+ (aq) + Cl (aq)
What is a soluble compound
A substance that dissolves in water
What is insoluble compound
It does not dissolve in water
What do the differences in solubility of ionic compounds depend on
Attractions of the ions to one another and the attraction of the ions to the water molecules
what is a solution
homogenous mixture of 2 or more substances
what is a solvent
what does the dissolving
what is an aqueous solvent
water is the solvent
what is a solute
what is being dissolved
what is an electrolyte
dissociates into ions when dissolved in water
what is a nonelectrolyte
many dissolve in water but it does not dissociate
what does a material need to conduct electricity
charged particles
what is an electrolyte solution
all contain ions dissolved in water
what is a nonelectrolyte solution
contain whole molecules dissolved in water
what happens when strong electrolytes dissolve in water
dissociates completely
what happens when weak electrolytes dissolve in water
only partially dissociates
what types dissociate in water
strong electrolytes
strong electrolytes =
strong acids
what are strong acids
undergo ionization reactions to produce H+ ions and anions that are represented in balanced chemical equations
what are the 7 common strong acids
- ) sulfuric (H2SO4)
- ) hydrochloric (HCL)
- ) Hydrobromic (HBr)
- ) Perchloric (HClO4)
- ) Chloric (HClO3)
- ) Hydroiodic acid (HI)
- ) Nitric Acid (HNO3)
strong acids and bases are
soluble
what is a soluble ionic compound
strong electrolytes
What is a balanced equation
equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge is the same for both the reactants and the products
what are weak acids
only partially dissociate, so they only
produce a low concentration of ions in solution
what equilibrium arrow is used for weak acids and bases
the one where it goes in both directions to show that the reaction does not complete
what are weak bases
partially dissociate
what categories can electrolytes be in
ionic or molecular
what are some examples of ionic strong electrolytes
soluble salts and strong bases
what is an example of a ionic nonelectrolyte
insoluble salts
what is an example of a molecular strong electrolyte
strong acids
what is an example of a weak molecular electrolyte
weak acids and weak bases
what is an example of a molecular nonelectrolyte
all other compounds
what is concentration
designates the amount of solute
dissolved in a given quantity of solvent or quantity of
solution
what is molarity
one way to measure the concentration of
a solution
what is the formula for Molarity (M)
moles of solute/ volume of solution in liters
what is the first step for making a concentrated solution
one weighs out a known
mass (which can be convert to
number of moles) of the solute
what is the 2nd step for making a concentrated solution
solute is added to a
volumetric flask, and solvent is
added to the line on the neck of
the flask
what is a stock solution
Solutions that are used routinely
in the lab are often prepared (or
purchased)
what is diluted
Solutions of lower concentrations
what happens if a dilute solution contains the same volume as a concentration solution
the relationship between the amount of solute and solvent must be different
how can someone dilute a concentrated solution
dilution
how does dilution work
use a pipet to deliver a specific amount of the concentrated solution to a new volumetric flask
- add solvent until the line on the neck of the flask is reached
what is the formula for dilution
molc=mold
Mc x Vc = Md x Vd
what is a precipitation reaction
reactions that result in the formation of an insoluble product
what is a precipitate
The insoluble
product
what is solubility
amount of that
substance that dissolves in a given quantity of
solvent at a given temperature
what are some soluble ionic compounds
Li+, Na+ K+, Cs+, Rb+, NH4+ (No exceptions)
what are some soluble ionic compounds
NO3-, C2H3O2- (none exceptions)
what are some soluble ionic compound
Cl-, Br-, I- (exceptions (Ag+, Hg2+2, Pb+2)
what are some soluble ionic compounds
SO4-2 ( Ca+2, Sr+2, Ba+2, Ag+2, Hg+2, Pb+2,
what are some insoluble ionic compoinds
S-2, OH-
what are some insoluble ionic compounds
CO3-2, CrO4-2, PO4-3
what is a molecular equation
shows the complete neutral
formulas and phases for each compound in the
aqueous reaction
what is a complete ionic equation
all strong
electrolytes (strong acids, strong bases, and
soluble ionic salts) are dissociated into their ions
what is another name for complete ionic equation
ionic equation
what does an ionic equation show
accurately reflects the species that are found in the reaction mixture
what is the net ionic equation
cross out anything
that does not change from the left side of the
equation to the right
what are spectator ions
those that didn’t change (deleted from the net ionic equation)
what is the other type of stoichiometry problem
molarity-molarity
what are some characteristics of acids
have a sour taste.
−Can dissolve many metals
−Ability to neutralize bases
what does the Latin word acidus mean
sour or tart
what are some characteristics of bases
have a bitter taste
- feel slipper to the touch
- ability to neutralize acids
where does the word base come from
english word which means to bring low
who was svante arrhenius
(`1880)
- swedish chemist
what was the arrhenius theory
acids are substances that increase the concentration of H+
bases are substances that increase the concentration of OH- when dissolved in water
what are some problems with arrhenius theory
1.) does not explain why molecular substances like NH3 and Na2CO3, Na2O dissolve in water
(bc they do not contain OH-ions)
2.) does not explain why molecular substances like CO2 dissolve in water
(they do not contain H+ ions)
3.) it does not explain acid-base reactions that take place outside aqeuous solutions
who were bronsted and lowry and what did they do
(1923)
- Johannes Bronsted was a danish chemist
-Thomas lowry was an English Chemist
they proposed a general definition of acids and bases
what was the bronsted-lowry theory
acids are proton donors
(must have a removable proton)
bases are proton acceptors
(must have a pair of nonbonding electrons)
what is a neutralization reaction
a solution of an acid and a solution of a base
are mixed
what does a neutralization reaction between acid and metal hydroxide produce
water and a salt
what is a salt
ionic compound whose cation comes from a base and the anion comes from an acid
what does cation mean
to lose an electron
what does anion mean
to gain electron
what is a titration
analytical technique in which one can
calculate the concentration of a solute in a solution.
what is standard solution
solution of a known concentration
what does titration involve
combing sample of unknown w/ standard solution
what is the equivalence point
point at which the two different solutions (known and unknown) are at stoichiometrically equivalent quantities.
what is used in acid-base titrations
indicators or dyes
why is equivalence point never found
acid-base titrations dyes and instead the end point is found
what reaction does precipitation, acid base, gas evolution rections involve
oxidation-reduction reaction
what is an oxidation-reduction
Reactions that involve transferring electrons from one
atom to another
what is oxidation
occurs when an
atom or ion loses electrons
what is reduction
an
atom or ion gains electrons.
when do redox reactions occur
in and out of solution
what is an example of redox reaction
rusting iron, bleaching hair, producing electricity
how can you determine if an oxidation-reduction reaction has occured
we assign an oxidation number
what can oxidation number help us with
determine the electron flow in the reaction
what are oxidations not
ion charges
what is the first rule of oxidation numbers
free elements = 0
Na, Be, K, Pb
in monatomic ions the oxidation number is equal to what
the charge on the ion
Li+ = +1
Fe+3 = +3
Group IA metals have a charge of
+1
Group 2A have a charge of
+2
aluminum is always
+3
what oxidation number do nonmetals have
negative
what is the oxidation number of hydrogen
+1 but -1 when bonded to metals
what is the oxidation number of O
-2
what is exception for oxygen
H2O2 bc it is -1
what oxidation numbers do halogens
-1
what is the sum of the oxidation numbers in a neutral compound
0
example:NaCl
what is the sum of the oxidation numbers on a polyatmic
The sum of the oxidation numbers in a polyatomic
ion is the charge on the ion
when does oxidation occur
atoms oxidation increases during reaction
when does a reduction occur
atoms oxidation state decreases during reaction
oxidation and reduction must occur…
simultaneously
what is a reducing agent
reduces an element in another
reactant is called the reducing agent.
- contains the element that is oxidized
what is an oxidizing agent
The reactant that oxidizes an element in another
reactant
-contains the element is reduced