Essay about acid base titration 1

Submitted By joebo420
Words: 459
Pages: 2

Acid Based Titration

Objective

The concentration of sodium hydroxide was determined by standardizing potassium hydrogen phthalate (KHP) in an acid based titration experiment using the following equation:

OH-(aq) + HP-(aq) → H2O(l) + P2-(aq)

Experimental Procedure

A solution containing 1 L of 0.05 M sodium hydroxide was prepared using a 1 L volumetric flask and 6 M sodium hydroxide. A small amount of the prepared solution was poured into a 50 mL buret in order to rinse the buret. The buret was then filled with the solution of sodium hydroxide to the 0.00 mL marking. An approximate mass of KHP (0.357 g) was calculated in order to react with 35 mL of 0.05 M sodium hydroxide. The mass of KHP was weighed (0.398 g) and placed in a 250 mL Erlenmeyer flask. Roughly 50 mL of distilled water was added to the flask to dissolve the solid. A phenolphthalein solution was added to the flask (1-2 drops). The initial buret reading was measured and recorded (0.00 mL). The sodium hydroxide solution in the buret was added to the solution in the Erlenmeyer flask. Enough sodium hydroxide solution was added so that the solution in the Erlenmeyer flask turned pink. The final buret reading was measured and recorded (44.2 mL). The procedure was repeated two more times (Table 1).

Data
Table 1: Mass of KHP and Volume of NaOH Solution used in Titration Experiment
Trials
Mass of KHP
(g)
Initial Buret Reading (mL)
Final Buret Reading (mL)
1
0.398
0.00
44.2
2
0.408
0.00
46.0
3
0.403
0.00
45.5

Calculations

Prelab

Molar Mass KHC8H4O4 = ( 1 mol K × 39.098 g/mol) + (5 mol H × 1.00794 g/mol) + (8 mol C × 12.011 g/mol) + (4 mol O × 15.9994 g/mol) = 204.22 g/mol

Moles = Molarity × Liters
Moles = 0.050 M × 0.035…