Kool-Aid contains Allura Red dye. A student makes a Kool-Aid solution by diluting 61.2 mg of Kool-Aid with water to a total volume of 25.00 mL using a volumetric flask. Because this solution is too concentrated (measured absorbance > 1.0), the student then dilutes a small sample of the Kool-Aid solution by taking 0.500 mL of the solution and mixing it with 0.500 mL of water (a ½ dilution). The absorbance of the ½ diluted solution is 0.315. Using the Beer’s Law curve, determine the concentration of the dye in the original Kool-Aid.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.