Volumetric analysis
exercise 10
Irene is given 200ml of 0.2M HCl solution. Her friend accidentally drops in some solid NaOH which quickly dissolves. A 20ml aliquot is taken and titrated against a 0.1M NaOH solution. The results are shown on the right.
Calculate the mass of NaOH accidentally dropped in to the 200ml solution.
Atomic mass Na =23, O =16, H=1
|
Volume
|
|
| Start |
12.40
mls
|
| Finish |
32.22
mls
|
| Total |
The equation for the reaction is shown below.
Step 1 Calculate
the mole of sodium hydroxide added
Mole = volume X concentration
Step 2 Using the equation calculate the number of mole of acid required to react completely
Step 3 Find
the mole of acid that should have been present in the 20ml aliquot of
a 0.2M solution
Mole= volume X concentration
Step 4 Find the mole of acid that reacted with the NaOH which was accidentally
dropped in to the solution. This will equal to the mole of NaOH that
was added.
Step 5 Calculate the mass of NaOH added.