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General
Check for the concentration of common acids and bases.
Experiments
1. Step 2 (Work-up)
"36% HCl" refers to concentrated hydrochloric acid. There is nothing such as 100% HCl! See link above.
In some instances, the reaction turned green in color and forms a second layer (usually on top) upon standing. It is advisable to repeat the experiment in such an event. Most likely, some of the methanol evaporated away, probably causing the phase separation. Keep in mind that the majority of the formaldehyde solution is water.
The extraction has to be performed in two batches since the suspension after additing the water does not fit entirely into the 125 mL separatory funnel.
The recrystallization step takes some time in any cases. Make sure that you dissolve the crude product and then place it in an Erlenmeyer flask, which is closed with parafilm.
2. Synthesis of Ce(OH)3(OOH) (Step 3a)
It is very important to add the 30% hydrogen peroxide slowly otherwise the mixture will foam heavily. The use of a burette would be advisable to control the addition.
Concentrated hydrogen peroxide is unstable and can decompose rapidly when it comes in contact with transition metals and/or bases. It also reacts violently with certain organic compounds. Careful!
You should check out a big Buechner funnel (from the lab support) for the filtration of the product. Since the product is a fine powder, the filtration usually is rather slow. In some cases, the filter paper clogs up entirely and has to be replaced several times. The volume of the precipitate decreases gradually as the water is removed by extraction.
The filtered product needs to be washed thoroughly with water and then with acetone in order to remove the majority of the water. A dry product affords better results in the subsequent oxidation.
When you dry the product unter the heat lamp, make sure not to heat it up too much and too long. Ce(OH)3(OOH) is thermally not very stable.