#4

Titration of 10.0 mL HCl-solution (with unknown concentration) with 0.113 mol/L NaOH(aq). The equivalence point is reached after adding 11.2 mL NaOH. 1. Calculate the original HCl-concentration. 2. Calculate the pH at the start of the titration (0 mL added). 3. Calculate the pH after adding 5.0 mL NaOH. 4. Calculate the pH after adding 11.2 mL NaOH (EP). 5. Calculate the pH after adding 15.0 mL NaOH.

a	Write the chemical reaction that occurs upon adding NaOH to HCl.
1a	How many moles of NaOH are present in 11.2 mL of 0.113 mol/L NaOH?
1b	How many moles of HCl were present at the start?
1c	Calculate the original HCl-concentration.
2a	What is HCl?
2b	Calculate the H+-concentration at the start.
2c	Calculate pH at the start.
3a	How many moles of NaOH are present in 5.0 mL of 0.113 mol/L NaOH?
3b	How many moles of HCl are left after the reaction?
3c	Calculate the H+-concentration after the reaction.
3d	Calculate pH at this moment.
4a	How many moles of NaOH are present in 11.2 mL of 0.113 mol/L NaOH?
4b	How many moles of HCl are left after the reaction?
4c	Calculate pH at this moment.
5a	How many moles of NaOH are present in 15.0 mL of 0.113 mol/L NaOH?
5b	How many moles of NaOH are left after the reaction?
5c	Calculate the OH--concentration after the reaction.
5d	Calculate pOH.
5e	Calculate pH.