Neutralization Reactions
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Transcript Neutralization Reactions
Neutralization Reactions
Ex: HCl + NaOH
NaCl + HOH
These are double replacement reactions
Ions switch partners. Water is formed.
http://www.youtube.com/watch?v=8IRI5gPR5EY&safe=active
Neutralization Forms Water
H+
from acid
+
OH-
from base
H 2O
neutral
This “net” reaction for neutralization is found
on Table I. It is an exothermic reaction.
Forming a Salt
(+) cation from the base
(-) anion from the acid
combine to form a salt.
If equal concentrations of hydrogen ion H+ and
hydroxide ions OH- are mixed, it results in a
neutral solution.
Ex:
.1M LiOH +
.1M HCl =
Neutral Solution
pH = 7
Completing and Balancing
Neutralization Equations
Write charges for ions in acid and base.
Switch ion partners. (+ ions stay in front!!)
Do not bring over subscripts except if part
of a polyatomic ion!
Criss-Cross charges to balance formulas.
Balance entire equation.
Name the acid, base and salt.
You Try It
Complete equation and balance formulas
Balance equation.
Name acid base and salt
Ex: KOH + H2SO4
KOH + H2SO4
HOH + K2SO4
Ex: Mg(OH)2 + HNO3
Mg(OH)2 + HNO3
HOH + Mg(NO3)2
Hydrolysis
Opposite reaction to neutralization
Salt + Water
Acid + Base
Parent Acid/Base
If you know the salt involved you should
be able to determine which acid and base
it would form if water is added.
Salt + Water
Acid + Base
Ex:
NaCl with water (HOH) would form HCl and NaOH
You Try It
Name the “parent” acid and base that
would be produced from these salts.
Ex:
Potassium chloride
Magnesium carbonate
Let’s Practice
Which substance is always a product when
an Arrhenius acid in an aqueous solution
reacts with an Arrhenius base in an
aqueous solution?
(1) HBr
(2) KBr
(3) H2O
(4) KOH
Which word equation represents a
neutralization reaction?
(1) base + acid → salt + water
(2) base +salt → water + acid
(3) salt + acid → base + water
(4) salt + water → acid + base
What are the products of a reaction
between KOH(aq) and HCl(aq)?
(1) H2 and KClO
(2) KH and HClO
(3) H2O and KCl
(4) KOH and HCl
Sulfuric acid, H2SO4(aq), can be used to
neutralize barium hydroxide, Ba(OH)2(aq).
What is the formula for the salt produced
by this neutralization?
(1) BaS
(3) BaSO3
(2) BaSO2
(4) BaSO4
Which compound could serve as a
reactant in a neutralization reaction?
(1) NaCl
(2) CH3OH
(3) KOH
(4) CH3CHO
Answer: 3
Titrations
Purpose:
To determine the concentration of an acid
or base through a neutralization reaction.
Acid/Base Titration
Buret is filled with a
“standard solution” of
known concentration (M).
Erlenmeyer Flask contains
solution of unknown conc..
Indicator (phenolphthalein)
added to the flask.
Acid/Base Titrations
Slowly “titrate” or drip liquid
into flask from buret until
indicator changes color.
This is the “endpoint” or
“equivalence point”.
(Moles H+ = Moles OH-)
Record total volume (V) used
from buret.
Titration Formula
MA x VA = MB x VB
Molarity Acid x Volume Acid = Molarity Base x Volume Base
Titration Applet
http://group.chem.iastate.edu/Greenbowe/se
ctions/projectfolder/flashfiles/stoichiometry
/acid_base.html
You Try It!
A 50 ml sample of .2M HCl is neutralized by
75ml of NaOH. What is the conc. of the base?
HCl
NaOH
.2M x 50ml = MB x 75ml
MB = .13M
Important Note
Multiply acid/base side of equation by
number of H+ or OH- ions it produces
when dissociating!!!
Ex:
H2SO4 produces 2 H+ so you would
multiply the acid side by “2”
You Try It!
How much of a .1M H2SO4 solution is
needed to neutralize 50 ml of a .05 KOH
solution?
H2SO4
KOH
2 x .1M x VA = .05M x 50ml
VA = 12.5 ml
Titration Demonstration
http://www.youtube.com/watch?v=5BZ0MPI
geEE&safe=active
Let’s Practice
During which process can 10.0 milliliters of
a 0.05 M HCl(aq) solution be used to
determine the unknown concentration of a
given volume of NaOH(aq) solution?
(1) evaporation
(2) filtration
(3) distillation
(4) titration
The data collected from a laboratory
titration are used to calculate the
(1) rate of a chemical reaction
(2) heat of a chemical reaction
(3) concentration of a solution
(4) boiling point of a solution
A student completes a titration by adding
12.0 ml of NaOH(aq) of unknown concentration
to 16.0 ml of 0.15 M HCl(aq).
What is the molar concentration of the NaOH(aq)?
(1) 0.11 M
(2) 1.1 M
(3) 0.20 M
(4) 5.0 M