1. An "jodide/chloride/sulfate'" unknown solution gave a yellow precipitate with aqueous AgNO3, and after centrifuging, the supernate gave no reaction with aqueous Ba(NO3)2. The yellow precipitate did not dissolve in aqueous NH4OH, and adding aqueous HNO3 gave no reaction. State the anion(s) confirmed present and absent in the unknown solution. nd Anion(s) present Anion(s) absent

A 2.2004 g of primary standard oxalic acid, H2C2O4 (90.04 g/mol), was dissolved in water to form a 250.00 mL solution. A 50.00 mL aliquot was taken for analysis and required 51.62 mL NaOH for titration. If the reaction is: H2C2O4 + 2NaOH ----> Na2C2O4 + 2H2O, what is the molarity of the NaOH solution?

One mL of an unknown solution is placed in a test tube and a few drops of NaOH are added and shaken well. 1 mL of aqueous NH3 is then added to the solution and shaken again. A deep blue solution is observed. What is the interpretation for this result? Select one: A. There is Iron(III) (Fe3+) present in the solution. B. There is Zinc (Zn2+) present in the solution. C. There is Copper(II) (Cu2+) present in the solution.

A sample of alfalfa meal weighing 2.0 g is analyzed by Kjeldahl method for the percentage of nitrogen. The liberated NH3 is caught in a solution of H3BO3, and 8.23 ml of HCl are required in the subsequent titration. A sample of pure (NH4)2SO4 (132.12) weighing 0.61 g is treated with excess NaOH and the liberated NH3 (17.04) is also caught in H3BO3. The resulting solution requires 20 ml of the acid for titration. Calculate the percentage of protein in the sample using 6.25 as the factor.