ALBUMIN CONCEN- BIURET REAGENT TOTAL STOCK (10 MG/ML) TUBE WATER TRATION ABSORBANCE (A) VOLUME (MG/ML) 1. Blank 5 ml. O mL 3 ml 2. Std. 1 4 mL 1ml 3 ml 0.1 3. Std. 2 3 ml 2 ml 3 ml 0.2 4. Std. 3 2 mL 3 ml 3 ml 0.3 5. Std. 4 1 ml. 4 mL 3 ml 0.4 6. Std. 5 O mL 5 ml 3 mL 1.5 5 ml of unk. + 3 mL of Biuret reagent Absorbance of unk. 7. Unk. Tube = 0.38 A

Show the chemical equation a. Tert-butylamine and nitrous acid test b. Aniline and nitrous acid test c. N-methylaniline and nitrous acid test

Part B: Miscibility of liquids 1. Place 10 drops of propan-2-ol into each of two DRY semi-micro test tubes. 2. Add 10 drops of water to one test tube and 10 drops of cyclohexane to the other test tube, shake and observe whether the two liquids in each test tube are miscible. Record your results then discard the contents of the test tubes into the organic waste container. 3. Place 10 drops of water in a clean semi–micro test tube and add 10 drops of cyclohexane to it. Record whether the two liquids are miscible. If two layers form (i.e. the liquids are immiscible) add a drop of blue food dye to the mixture and shake, then allow the two layers to reform. Based on your observation, decide whether the food dye is more soluble in water or cyclohexane and then discard the mixture into the non–halogenated waste container. Record whether the combinations of liquids shown below are miscible. Water Cyclohexane Propan-2-ol Cyclohexane

In one procedure it says, "Pour the organic layer into a clean, dry 50-mL Erlenmeyer flask, add 2 g of calcium chloride..." What is the purpose of the calcium chloride?