chm2045exam1

# chm2045exam1 - CHM 2045 Exam 1 Gower Mitchell Ucak...

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CHM 2045 Exam 1( Gower, Mitchell, Ucak, Harrison) (Form Code A) corrected September 17, 2009 Instructions: On your scantron sheet enter your name, UF ID number (start on the first space and leave the last space blank), Discussion Section No. and Form Code (see above). This exam consists of 25 multiple choice questions each worth 10.0 points for a total maximum of 250 pts. You may retain your exam sheet (mark your answers on it and the scantron 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. A solution of sucrose in water is 28.0% sucrose by mass and has a density of 1.118 g/mL. What mass of sucrose, in grams, is contained in 3.50 L of solution? 1) 5.5 x 10 2 g 2) 1.1 x 10 3 g 3) 1.9 x 10 3 g 4) 3.1 x 10 3 g 5) 3.9 x 10 3 g 2. Silver has two naturally-occurring isotopes with masses of 106.905092 amu and 108.904756 amu. What are the percent abundances of each isotope, respectively? (1) 27.45 ; 72.55 (2) 50.25% ; 49.75% (3) 62.15% ; 37.85% (4) 15.84 ; 84.16 (5) 78.64 ; 21.36 3. What mass of oxalic acid, H 2 C 2 O 4 , is required to make 250. mL of a 0.0500 M solution? 1) 1.13 g 2) 2.81 g 3) 3.15 g 4) 4.21 g 5) 0.723 g 4. A mixture of butene, C 4 H 8 , and butane, C 4 H 10 , is combusted in air to give carbon dioxide and water. Suppose you burn 5.72g of the mixture and obtain 17.60 g of CO 2 . What is the mass of butene closest to in the mixture? C 4 H 8 (g) + 6 O 2(g) 4 CO 2(g) + 4 H 2 O (g) ; 2 C 4 H 10 (g) + 13 O 2(g) 8 CO 2(g) + 10 H 2 O (g) 1) 1.09 g butene 2) 1.59g butene 3) 2.54 g butene 4) 1.11 g butene 5) 1.28 g butene 5. The vitamin C, (C 6 H 8 O 6 ) content in a tablet is analyzed by a reaction with bromine and then titration of the hydrobromic acid with standard base: C 6 H 8 O 6 + Br 2 C 6 H 6 O 6 + 2HBr HBr + NaOH NaBr + H 2 O One tablet was dissolved in water and reacted with bromine. The solution was then titrated with 53.20mL of 0.1350 M NaOH. How much Vitamin C did the tablet contain in mg?

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chm2045exam1 - CHM 2045 Exam 1 Gower Mitchell Ucak...

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