Neutralization Reactions

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Neutralization Reactions

• Ex HCl NaOH NaCl HOH

2

• These are double replacement reactions
• Ions switch partners. Water is formed.

http//www.youtube.com/watch?v8IRI5gPR5EYsafeac
tive
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Neutralization Forms Water

• H OH- ?? H2O
• from acid from base neutral
• This net reaction for neutralization is found
• on Table I. It is an exothermic reaction.

4
Forming a Salt

• () cation from the base
• (-) anion from the acid
• combine to form a salt.

5

• 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

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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.

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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

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Hydrolysis

• Opposite reaction to neutralization
• Salt Water Acid Base

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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

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You Try It

• Name the parent acid and base that would be
  produced from these salts.
• Ex Potassium chloride
• Magnesium carbonate

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Lets 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

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• 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

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• 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

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• 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

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• Which compound could serve as a reactant in a
  neutralization reaction?
• (1) NaCl    
• (2) CH3OH
• (3) KOH    
• (4) CH3CHO

16

• Answer 3

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Titrations

• Purpose
• To determine the concentration of an acid or
  base through a neutralization reaction.

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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.

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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.

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Titration Formula

• MA x VA MB x VB
• Molarity Acid x Volume Acid Molarity Base x
  Volume Base

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• Titration Applet
• http//group.chem.iastate.edu/Greenbowe/sections/p
  rojectfolder/flashfiles/stoichiometry/acid_base.ht
  ml

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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

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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

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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

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• Titration Demonstration
• http//www.youtube.com/watch?v5BZ0MPIgeEEsafeac
  tive

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Lets 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

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• 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

28

• 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