a) 15.0 mL of the sodium hydroxide solution added
b) 25.0 mL of the sodium hydroxide solution added
c) 35.0 mL of the sodium hydroxide solution added© BrainMass Inc. brainmass.com October 17, 2018, 10:12 am ad1c9bdddf
In any multiple step titration problem it is important to calculate the equivalent volume, before attempting to solve the problem. Sodium hydroxide (NaOH) is a strong base and hydrochloric acid (HCl) a strong acid. The reaction is shown below:
NaOH (aq) + HCl (aq) => NaCl (aq) + H2O (l)
The balance equation shows a 1:1 ration between the acid and the base and can be represented by this simple formula;
MaVa = MbVb where Ma and Mb are molarity of base and acids respectively and Va and Vb are volumes of base and acid. The equivalent volume, i.e. the amount of base added to attend equilibrium is Ve = Vb.
Ve = Vb = MaVa/Mb ...
A solution present strong acid, strong base titrations at three important stages. First being before equivalent point, where there is excess acid, then at equivilant point where there is equal amount of acid and bases and finally after equivalent point where there is excess base.
Weak acid/strong base titration
What is the pH at the equivalence point when when 25.0 mL of 0.175 mol/L HNO2(aq) is titrated with 0.137 mol/L NaOH(aq)? Assume the temperature is 25C. (For HNO2, pKa=3.14 at 25C).
Give your answer accurate to two decimal places.View Full Posting Details