Summary - Unit 2- Practical Scientific Procedures and Techniques

UNIT 2
Assignment A Titration and Colorimetry
Standard Solution
A titration is an experiment through which the concentration of an unknown acid or
alkali can be calculated.
Equipment:
1. Weighing boat
2. Balance
3. Sodium carbonate
4. Beaker
5. Water
6. Stirring pod
7. Funnel
8. Volumetric flask

Method: Sodium carbonate standard solution
1. Place the weighing boat on the balance. Set the balance to zero. Weigh the
sodium carbonate; it should be between 2-3g.
2. Place this in a beaker, add about 50 cm3 of water, and stir with a stirring rod to
dissolve the solid.
3. Riser the sodium carbonate on the weighing boat using water
4. When the sodium carbonate is fully dissolved in the solution, transfer the solution
using a funnel into a volumetric flask
5. Ring the beaker and glass rod with water
6. Fill the volumetric flask with water, when the water is close to the meniscus line
and water drop by drop until the solution reaches the meniscus line to ensure it
does not go over the meniscus line.
7. Put the stopper on the flask and invert the flask a few times to mix the solution.
8. Label the solution with your name.
Calculations:
1. Equation: Na2CO3+ 2HCL -> 2NaCl + H2O + C02
2. Concentration of Na2CO3 0.025/250 x 1000 = 0.1 moldm3
3. Moles of Na2CO3 in 250cm3=0.025, moles in 25cm3 -0.025/10 = 0.0025