A 15000 L tailings pond at a mine site was analyzed for cadmium contamination. First, a 25.0 mL sample of water was removed from the pond. Then the solution was evaporated to dryness, and 56.1 mg of cadmium was recovered (the identity of the metal was confirmed through other methods). Assuming the water is homogeneously distributed throughout the pond, what is the concentration of cadmium in the tailings pond?

A sample containing a mixture of CuCl2(s) and KCI(s) with a mole fraction of 13.8% KCI was dissolved in water. An excess of AgNO3(s) is added to the mixture, resulting in the chloride being precipitated as AgCl(s). The AgCl(s) is collected and dried, weighed to have a mass of 8.40g. Calculated the masses of KCI(s) and CuCl2(s) in the original mixture.

As shown in the following Figure, an aqueous solution of Nal is poured into an aqueous solution of Pb(NO3)2 which results in the formation of a yellow precipitate. Assuming stoichiometric amounts of Nal and Pb(NO3)2 are reacted, give the chemical formula of the yellow precipitate and the chemical formula of all molecules and/or ions that are present in the solution (You may use the solubility matrix to answer this question). (b)

Most analytical machines used in science can either measure absorbance of light, like the spectrophotometers used BioZ 151 and 152 labs, or can measure change in electrical conductance. In order to convert things like absorbance values into concentration data, a linear regression is used. In order to determine nitrite concentration in water samples, nitrite is reacted with several chemicals to produce a purple color. The absorbance of the solution is measured from known amounts of nitrite to produce a standard curve to analyze samples. Use the data in the provided table, or from the linked spreadsheet to make a graph and perform a linear regression using treadline. mg/L NO3 Absorbance 0 0.1 0.3 0.5 0.7 o 0.183 0.542 0.914 1.298) 1.61) In order for this to work, samples must be diluted prior measurement so that the concentration falls within the range of the standard curve. If a sample underwent a 30 dilution, and produce an absorbance value of 0.953, what is the resultant concentration…