Freon-12 ccl2f2, is prepared from ccl4 by reaction with hf. the other product of this reaction is hcl. outline the steps needed to determine the prcent yield of a reaction that produces 12.5 g of ccl2f2 from 32.9 g of ccl4. feron-12 has been banned and is no longer used as a refrigerant because it catalyzes the decomposition of ozone an d has a very long lifetime in the atmosphere. determine the percent yield.

In an energy pyramid, which level has the most available energy?

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.

State one important difference between a physical change and a chemical change?