chm 2045 quiz2 B - density of the pure water is 1.00 g/mL...

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CHM 2045 Quiz #2 09/27/2007 Name: Section: Question # 1 Here is the reaction of calcium carbonate and hydrochloric acid: CaCO 3 (s) + 2HCl(aq) CO 2 (g) + CaCl 2 (aq) + H 2 O(l) (a) What type of reaction is this? (1 point) (b) What mass of CaCO 3 will completely react with 400mL of HCl(aq) with a pH of 0.60? (3 points) Question # 2 Please write down the (1) reducing agent; (2) oxidizing agent; (3) net ionic equation of the following overall equations (6 points) (a) Zn (s) + 4HNO 3 (aq) Zn(NO 3 ) 2 (aq) + 2NO 2 (g) + 2H 2 O (l) (b) 4Au(s) + 8NaCN (aq) + O 2 (g) + 2H 2 O (l) 4NaAu(CN) 2 (aq) + 4NaOH (aq) Question # 3 Four 40-g copper cubes at 354.6 ° C are dropped into 1L of pure water to make them cool. The pure water was initially at 10.0 ° C; when thermal equilibrium was reached, the final temperature was 15.0 ° C. Please calculate the specific heat capacity of copper. (Assume the
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Unformatted text preview: density of the pure water is 1.00 g/mL and the temperature change has no effect on it. The specific heat capacity of pure water is 4.184 J/g·K) (5 points) Question # 4 The standard molar enthalpy of formation of benzene, C 6 H 6 (g), cannot be determined directly because the compound cannot be prepared by the reaction of carbon and hydrogen. It can by calculated from other enthalpy changes, however. The following enthalpy changes can be measured: Equation 1: C(s) + O 2 (g) CO 2 (g) Δ H° rxn = -393.5 kJ Equation 2: 2H 2 (g) + O 2 (g) 2H 2 O (l) Δ H° rxn = -571.6 kJ Equation 3: 2C 6 H 6 (g) + 15O 2 (g) 12CO 2 (g) + 6H 2 O (l) Δ H° rxn = -6534.7 kJ Please use these energies to obtain the Δ H° f of benzene. (5 points)...
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This note was uploaded on 04/24/2008 for the course CHM 2045 taught by Professor Mitchell during the Spring '07 term at University of Florida.

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