Internal standard. A solution was prepared by mixing 5.00 mL of unknown element X with 2.00 mL of solution containing 4.13 g of standard element S per milliliter, and diluting to 10.0 mL. The signal ratio in atomic absorption spectrometry was (signal from X)/ (signal from S) 0.808. In a separate experiment, with equal P concentrations of X and S, (signal from X)/(signal from S) 1.31. Find the concentration of X in the unknown.
Chapter 16 - Spontaneity, Entropy, and Free Energy 16.1 Spontaneous Processes and Entropy A. First Law 1. "Energy can neither be created nor destroyed" 2. The energy of the universe is constant B. Spontaneous Processes 1. Processes that occur without outside intervention 2. Spontaneous processes may be fast or slow a. Many forms of combustion are fast b. Conversion of diamond to graphite is slow C. Entropy (S) 1. A measure of the randomness or disorder 2. The driving force for a spontaneous process is an increase in the entropy of the universe 3. Entropy is a thermodynamic function describing the number of