Preparation of Copper II Fluoride

Preparation of Copper(II) Fluoride. Work with hydrofluoric acid in a fume cupboard in rubber gloves, using platinum or lead ware. 

To measure a definite volume of hydrofluoric acid, you can use an ordinary clean and dry glass measuring cylinder whose inner walls have been coated with a thin layer of paraffin. How does hydrofluoric acid react with glass  

5 g of copper(II) oxide into a platinum bowl and add the calculated amount of an approximately 35% hydrogen fluoride solution, taking an excess of 10-15%. If the reaction proceeds very slowly, put the bowl on a hot water bath. Filter the solution, inserting the filter into a lead, copper, or platinum funnel, and evaporate it until crystallization begins. Filter off the precipitate and wash it twice with cooled distilled water. Determine the yield in per cent. 

Preparation of Copper(II) Nitride. Assemble an apparatus (see Fig. 84). Use an electrical furnace to heat reaction tube 8. Put 2 g of copper(II) fluoride into porcelain boat 7 and place the latter into the reaction tube of the apparatus. Pass a stream of dry ammonia through the apparatus. Switch on furnace 6 and in half an hour the furnace used to heat tube 8, heating the latter to 280 °C. Why should not the temperature be increased above 300 °G When the reaction terminates (how can you determine this ), cool the apparatus in an ammonia stream. Put a small part of the product into a test tube and 

Preparation of Copper(II) Bromide. Introduce 1-2 g of a copper powder into a beaker with 50 ml of water and while stirring the reaction mixture, slowly add 3-6 drops of bromine from a dropping funnel. When the reaction terminates, cool the solution, filter it through ordinary cotton wool inserted into a glass funnel, boil it with charcoal (for what purpose ), and evaporate it in a vacuum desiccator. Filter off the formed crystals on a funnel with a filtering bottom. What is the composition of the product Write the equation of the reaction. Test how the copper bromide crystals behave in water and when heated. To do this, put 5-6 small crystals of the salt into each of two test tubes. Carefully add water dropwise to one of the tubes until the solution acquires a light blue colour, and then introduce about 0.2 g of dry potassium bromide, and heat the second tube. What happens Explain the observed phenomena. 

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Preparation of Copper(II) Fluoride (256). 2. Preparation of Copper(II) Nitride (256). 3. Preparation of Copper(II) Bromide (257). 4. Preparation of Copper(II) Acetylide (257). 5. Preparation of Silver from Silver Chloride (257). 

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