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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 turns green in color and a phase separation is observed 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 addition of the water does not fit entirely into the 125 mL separatory funnel. How much solvent is appropriate here to use for extraction? (Hint: see chapter about "Extraction Theory" in appendix of your reader)
The organic layer should be extracted once with water before treated with saturated sodium chloride solution and drying it over Na2SO4. This step permits to remove more of the unreacted formaldehyde from the organic layer.
The removal of the solvent should be aided by applying an air stream.
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)
You will need to check out large spin bar, Buechner funnel and a burette from the lab support for that.
It is very important to add the 30% hydrogen peroxide slowly otherwise the mixture will foam heavily. The use of a burette would be highly 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!
A big Buechner funnel is used 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.
The wet product is placed in a beaker that is placed in an oven (T ~45-50 oC). Make sure that you label your beaker properly. It can stay in there over night, but should be remove the next day. Ce(OH)3(OOH) is thermally not very stable.