1. Precipitate used in the gravimetric determination of uranium include Na2U2O7 (634.0 g/mol), (UO2)2P2O7 (714.0 g/mol), and V2O5-2UO3 (753.9 g/mol). Which of these weighing forms provides the greatest mass of the precipitate from a given quantity of uranium?

2. A 0.2121-gram sample of organic compound was burned in a stream of oxygen and the CO2 produced was collected in a solution of barium hydroxide. Calculate the percentage of carbon in the sample if 0.6006 gram of BaCO3 was formed.

3. A 5.000 grams sample of a pesticide was decomposed with metallic sodium in alcohol and then liberated v/chloride ion was precipitated as AgCl. Express the results of this analysis in terms of percent DDT (C14H9Cl5) based on the recovery of 0.1606 gram of the AgCl.