Neutralization, Titration &
Concentration
Neutralization
• For an acid to effectively neutralize a base (or
vice versa) the number of moles of acid and
base must be equal
Example
• How many moles of sodium hydroxide are
required to neutralize 45.0 mL of a 0.120
mol/L H2SO4 solution?
• 1. Write a balanced equation.
2NaOH(aq) + H2SO4(aq)  2H2O(l) + Na2SO4(aq)
2. Determine the # of moles to be neutralized
(calculate the number of moles of H2SO4)
2NaOH(aq) + H2SO4(aq)  2H2O(l) + Na2SO4(aq)
3. Use the coefficients to calculate the number of
moles required for neutralization.
Extension
2NaOH(aq) + H2SO4(aq)  2H2O(l) + Na2SO4(aq)
4. If you used 30.0 mL of NaOH to neutralize the
H2SO4, what is the concentration of the
NaOH?
Titrations
• Requirements:
– Standard  an acid or base where you know the
[concentration]
– Indicator  a substance in which the completed
titration (change from acidic to basic or vice versa)
will be demonstrated by a colour change
Titrations cont’d
• When the concentration of the acid and the
base are equal, we have reached the
“equivalence point”
• This is where:
#Moles acid = #moles base
The end point is reached when one drop of titrate
permanently changes the colour of the indicator
• Vinegar (aka Acetic Acid) was titrated with Sodium
Hydroxide to determine the concentration of acetic
acid present. A volume of 41.6 mL of 1.00 mol/L
NaOH was required to neutralize a 50.0 mL sample
of vinegar, indicated by a pink colour change. What
was the concentration of the vinegar?
• 1. Write a balanced equation
2. Calculate the moles of the standard that were
required to neutralize the unknown
concentration of vinegar
* At the equivalence point the moles acid =
moles base
NaOH(aq) + CH3COOH(aq)  CH3COONa(aq) + H2O
3. Use the coefficients to figure out the mole
ratio (notice it is 1:1 in this equation and
therefore #moles CH3COOH = #moles NaOH
Calculate the concentration of CH3COOH
Example:
• How many moles of sodium hydroxide are
required to neutralize 0.20 moles of nitric
acid?
Example:
• How many millilitres of 0.45 mol/L HCl solution
must be added to 25.0 mL of a 1.00 mol/L KOH
solution to make a neutral solution?