# Exam 2 - CHM 3120 Exam 2(Form Code A Instructions On your...

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CHM 3120 Exam 2 (Form Code A) February 26, 2009 Instructions: On your scantron sheet enter your name, UF ID number (start on the first space and leave the last space blank), and Form Code (see above). This exam consists of 20 ( + 2 bonus ) multiple choice questions each worth 10 points for a total maximum of 200 (+20) pts. You may retain your exam sheet. Turn in only the scantron. Bubbling errors of any kind will count as an incorrect response or result in the loss of points. 1 . Calculate H at 25 °C given the following: K = 2.000 x 10 6 (R = 8.314472 J * K 1 mol 1 ) HCl (g) H + (aq) + Cl (aq) S = -130.4 J/ (K . mol) at 25 °C (1) -41.35 kJ/mol (2) -40.35 kJ/mol (3) -38.84 kJ/mol (4) -87.85 kJ/mol (5) -74.85 kJ/mol 2. Calculate the ionic strength of a Cd(NO 3 ) 2 aqueous solution (0.050 M, 100 mL): (1) 0.30 M (2) 0.15 M (3) 0.015 M (4) 0.30 M (5) 0.45 3. FDA uses Kjeldahl analysis to determine protein concentration in milk. A typical milk sample has a protein concentration of 33.3 mg/mL and the protein in milk contains 15.6 wt% nitrogen. Because Kjeldahl Analysis cannot distinguish the source of nitrogen, addition of melamine (126.12 g/mol) into milk samples can cheat the FDA test for a higher protein concentration. A criminal milk supplier wants to combine 1.00 L of fresh milk, melamine and water to make 2.00 L of tainted milk. How much melamine is needed? (Molar Mass of Nitrogen = 14.0067 g /mol) (1) 7.80 g (2) 46.8 g (3) 15.6 g (4) 31.2 g (5) 23.4 g 4. Which of the following statements is incorrect. (1)

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Exam 2 - CHM 3120 Exam 2(Form Code A Instructions On your...

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