Bang-O is known to be an organic pesticide that contains 10.45% Cl. A 0.827 g sample containing the pesticide and an inert material with no chloride was decomposed with metalllic sodium in alcohol. the freeed-up chloride ion was precipitated in the form of AgCl that weighs about 0.0721 g. Calculate the percentage of pesticide in the given sample.

A 2.5624-g sample of a pure solid alkali metal chloride is dissolved in water and treated with excess silver nitrate. The resulting precipitate, filtered and dried, weighs 3.03707 g. What was the percent by mass of chloride ion in the original compound? What is the identity of the salt?

Polychlorinated biphenyls (PCBs) have been used extensively as dielectric materials in electrical transformers. Because PCBs have been shown to be potentially harmful, analysis for their presence in the environment has become very important. PCBs are manufactured according to the following generic reaction: C12H10+nCl2C12H10nCln.+nHCl This reaction results in a mixture of PCB products. The mixture is analyzed by decomposing the PCBs and then precipitating the resulting Cl asAgCl. a. Develop a general equation that relates the average value of n to the mass of a given mixture of PCBs and the mass of AgCl produced. b. A 0.1947-g sample of a commercial PCB yielded 0.4791 g of AgCl. What is the average value of n for this sample?

A solid forms when excess barium chloride is added to 21 mL of 3.5 M ammonium sulfate. Write the overall equation, and calculate the mass of the precipitate.

A mixture consisting of only sodium chloride (NaCl) andpotassium chloride (KCl) weighs 1.0000 g. When the mixtureis dissolved in water and an excess of silver nitrate isadded, all the chloride ions associated with the originalmixture are precipitated as insoluble silver chloride (AgCl).The mass of the silver chloride is found to be 2.1476 g.Calculate the mass percentages of sodium chloride andpotassium chloride in the original mixture.

Separate samples of a solution of an unknown soluble ionic compound are treated with KCl, Na2SO4, and NaOH. A precipitate forms only when Na2SO4 is added. Which cations could be present in the unknown soluble ionic compound?

Consider a 1.50-g mixture of magnesium nitrate and magnesium chloride. After dissolving this mixture in water, 0.500 M silver nitrate is added dropwise until precipitate formation is complete. The mass of the white precipitate formed is 0.641 g. a. Calculate the mass percent of magnesium chloride in the mixture. b. Determine the minimum volume of silver nitrate that must have been added to ensure complete formation of the precipitate.

42. a. Fill in the following table as if it is a well plate and you are mixing two aqueous compounds at a time to see if a precipitate forms. If a precipitate is expected to form, indicate that by writing the correct formula for the precipitate in the corresponding box in the table. If no precipitate is expected to form, write “NO” in the box. CaCI2 Pb(NO3)2 (NH4)3PO4 Na2CO3 AgNO3 K2SO4 b. How do you prepare 300.0 mL of a 0.250 M CaCl2 solution using an available 2(X) M solution? Support your answer with calculations, but also make sure you describe how to prepare the solution.

39. Standard solutions of calcium ion used to test for water hardness are prepared by dissolving pure calcium carbonate. CaCO3, in dilute hydrochloric acid. A 1.745-g sample of CaCO3 is placed in a 250.O-mL volumetric flask and dissolved in HCI. Then the solution is diluted to the calibration mark of the volumetric flask. Calculate the resulting molarity of calcium ion.

In most of its ionic compounds, cobalt is either Co(II) or Co(III). One such compound, containing chloride ion and waters of hydration, was analyzed, and the following results were obtained. A 0.256-g sample of the compound was dissolved in water, and excess silver nitrate was added. The silver chloride was filtered, dried, and weighed, and it bad a mass of 0.308 g. A second sample of 0.416 g of the compound was dissolved in water, and an excess of sodium hydroxide was added. The hydroxide salt was filtered and heated in a flame, forming cobalt(III) oxide. The mass of cobalt(III) oxide formed was 0.145 g. a. What is the percent composition, by mass, of the compound? b. Assuming the compound contains one cobalt ion per formula unit, what is the formula? c. Write balanced equations for the three reactions described.