Collected Volume sodium carbonate (mL) Molarity sodium carbonate (M) Volume calcium chloride (mL) 100 Molarity calcium chloride (M) Observations + Mass filter paper (g) Mass filter paper + precipitate (g) Calculated Observed mass calcium carbonate (g) Identify limiting reactant Expected mass calcium carbonate (g) Percent yield (%) How to calculate theoretical yield and percent yield MY NOTES

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?

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 percent yield of a reaction that produces 12.5 g of CCl2F2 from 32.9 g of Cd4. Freon-12 has been banned and is no longer used as a refrigerant because it catalyzes the decomposition of ozone and has a very long lifetime in the atmosphere. Determine the percent yield.

Ammonia can be formed from a combination reaction of its elements. A small fraction of an unreacted mixture of elements is illustrated in the following diagram, in which white spheres represent hydrogen atoms and blue spheres represent nitrogen atoms. The temperature is such that all species are gases. a Write and balance the equation for the reaction. b Which of the following correctly represents the product mixture? c Which species is the limiting reactant? Explain.

list at least three quantities that must be conserved in chemical reactions.

When lead(II) sulfide is heated lo high temperatures in a stream of pure oxygen gas, solid lead(II) oxide forms with the release of gaseous sulfur dioxide. Write the unbalanced chemical equation for this reaction.

Calculate the amounts of reactants needed in a chemical reaction to produce a specified amount of product.

A natural brine found in Arkansas has a bromide ion concentration of 5.00 × 10−3 M. If 210. g Cl2 were added to 1.00 × 103 L of the brine, determine the limiting reactant. calculate the theoretical yield of Br2 (d = 3.12 g/mL).

Write the balanced chemical equation for the complete combustion of adipic acid, an organic acid containing 49.31% C, 6.90% H, and the remainder O, by mass.

Consider the following particulate-level representation of a chemical equation: The white spheres represent hydrogen atoms, the black sphere represents a carbon atom, and the red spheres represent oxygen atoms. a Write a balanced chemical equation representing this reaction. b Write a word description of the reaction on the particulate and molar levels.