Topic > Intermediate Inorganic Laboratory - 336

Intermediate Inorganic LaboratoryExperiment 1:Preparation of sodium peroxoborateThe experiment is designed to form the salt of a peroxyacid (sodium peroxoborate) from a salt (sodium borate) and hydrogen peroxide.The Chemicals needed for the experiment are as follows: 4.75 g.sodium borate, 1.0 g. NaOH, 5.75 mL 30% sodium hydroxide, 12 mL 0.1M HCl, 10 mL 0.1N KMnO4, 0.2 g. KI, 5 ml of alcohol and 5 ml of ether. The only equipment required is a 150 mL beaker, 125 mm test tubes, a Buchner funnel, a filter flask, and an ice bath. Prepare sodium metaborate by dissolving 4.75 g. of borax (sodium borate) and 1.0 g. of sodium hydroxide in 20 ml of hot water. It may take some time for the sodium metaborate to dissolve, so in the meantime measure 5.75 ml of hydrogen peroxide and cool in an ice bath. Once the NaBO2 has completely dissolved, place the flask in the ice bath. Dilute the refrigerated hydrogen peroxide with 15 mL of deionized water. Slowly add the diluted hydrogen peroxide, drop by drop, stirring. After adding all the H2O2, continue mixing for about 15 minutes. Filter the crystals by aspiration using a Buchner funnel and wash with 5 mL of alcohol, then 5 mL of ether. Weigh the product. Weigh two pieces of 0.100 g. samples of the product and place each in a test tube. Add 6 ml of 0.1 M HCl to the first tube, then 0.1 M KMnO4 and record the results. Also add 6 ml of 0.1 M HCl to the second test tube. Prepare a 0.165 g solution. of KI in 10 ml of water. Add the KI solution dropwise to the test tube and record the results. I started with 4,750g. of borax, and produced 9.119 g. in the product. The product, NaBO3H2O, was a fine white powder. My percentage return was 79.0%. In the section where HCl and KMnO4 are added, the HCl dissolved the solid and when KMnO4 was added, the test tube was covered