An unknown solution may contain one or more of the following anions ( SO42-, PO43-, Cl-, and NO3-): A student received a sample of the above unknown and then performed the required procedure to determine which anion in the unknown as following: 1st half of the sample: a) The addition of aqueous barium nitrate to the basified solution yields a white precipitate which then separated from the solution (the solution kept for step b) by the centrifuge. The precipitate was dissolved by the addition of HNO3. The solution was separated from the remaining solid and treated with ammonium molybdate which results in the formation of a yellow precipitate. b) The solution was acidified with 6M HCl before the addition of aqueous silver nitrate which forms a precipitate. This precipitate is then basified with 6M aqueous ammonia and the precipitate completely dissolves. 2nd half of the sample: An unknown solution was acidified with 6M H2SO4. no observation was shown after the addition of excess FeSO4 solution and Conc. H2SO4. Which anions were present in the student’s unknown? Select one or more: SO42- PO43- Cl- NO3-

13. calculate the initial concentration (before precipitation) of carbonate ions after the addition of each 0.05 ml of solution b to the 1.00 l beaker of solution a. divide the work among group members and write the answers in the table in model 3. assume the volume change as solution b is added is negligible. 14. notice the initial concentrations of zn2+ - and cu2+ in the table in model 3. a. explain how these were obtained from the data in model 2. b. as solution b is added and precipitates form, do these initial concentrations change? 15. use the data in model 2 to indicate the presence of precipitate (either znco3 or cuco3) after each 0.05 ml addition of solution b in model 3. 16. use the initial concentrations of carbonate ions and zinc ions to calculate the reaction quotient, qsp for the zinc carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3. 17. use the initial concentrations of carbonate ion and copper(ii) ions to calculate the qsp for the copper(ii) carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3.

An atom of lithium (li) and an atom of chlorine (cl) engage in a chemical reaction. which correctly describes the structure of the resulting chemical compound? hint: consider the class of each element. the chemical compound will have a network structure. the chemical compound will have triple bonds. the chemical compound will have a ball-and-stick structure. the chemical compound will have double bonds.

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange