Exam 2 Solutions for General Chemistry | CHEM 151, Exams of Chemistry

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A. CHEM 151 EXAM 2 FORM CH FOR MULTIPLE CHOICE QUESTIONS: CIRCLE THE BEST ANSWER (a-e) FOR QUESTIONS INVOLVING CALCULATIONS, BE SURE TO SHOW YOUR WORK! INCLUDE UNITS. NO CREDIT IS GIVEN IF WORK IS NOT SHOWN! Which is the correct thermochemical equation representing the standard enthalpy of formation of (4 points) H20(1)? a) 2H(g) + O(g) ----> H20(1) b) 2Ha(g) + O2(g) ----> 2H20(1) c) Hy0(1) ----> He(g) + 1/202(g) @ H2(g) + 1/202(g) ----> H20(1) e) none of the above (4 points) A change occurs for a system and q = -43@ 3 and W = -13@ J. @) Work is done by the system. b) Work is done on the system, c) Heat is absorbed from the surroundings. d) The internal energy increases. e) Both a and c. (4 points} The rate of diffusion of helium gas is 5 times greater than the rate of diffusion of gas X. The molar mass of X is a) 2 b) 6 c) 28 5e d) (@) 100 (4 points) Ammonia can be prepared from gaseous bane Seet Z,. No(e) + 3Ha(g) ~---> 2NFG(g) What volume of hydrogen gas would be a) 2.8L wt b) 4.0L c) 8@L @ 6a e) 42L he f 4 O.G¥ Qt ra vif CAD i § nitrogen and hydrogen according to the following equation required to react with 2.@ L of nitrogen?