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QUESTIONS 1 - 20,3.5 POINTS EACH 1. Which of the following has a AHºr=0? AN) BOC) C.1.0 MH(aq) D. O2(g) E. none is on 2._ If a reaction is carried out under constant pressure conditions, it's always true that A. q- AH B.4-AE C.4"W D. both A and C are correct D. none of the answers is com 3. 0.103 g zinc reacts with 50.0 ml. of an hydrochloric acid solution (an excess of HCT) in a constant presses calorimeter, raising the solution temperature from 22.5 to 23.7 °C. The reaction is Zn(s) 2 HCl(aq) → H3(g) - ZnCl(aq). Calculate the enthalpy change AH in kJ/mole for this reaction Solution data: density - 1.0 gmc 4.18 J/g °C. A.-251 B.- 159 C. 251 D. 159 E. none is correct 4. Which type of electromagnetic radiation has the lowest frequency? A blue light B. red light C. infra-red light D. ultra-violet light E. X-rays 5. Calculate the energy (in kJ/mole electrons) when the electron in the hydrogen atom transitions from th ground state to the n = 3 level? A. - 1.17 x 10 B. - 2.15 x 106 C. 1.17x 10 D. 2.15 x 10 E. None is correct 6. The take-home message of the photoelectric effect experiment is that... A. Light is a wave and electrons are particles B. Orbitals are electrons circling around the nucleus C. Electrons are pure energy (waves) until collapsed into particles D. Electrons cannot be removed from their nucleus simply by shining light E. Electrons will have a kinetic energy equal to their work-function

Answer 1

0 D) 02 (1) D both Adc Total Mass = 50 +0.103 = 50.1039 dT = 23.7 -22.5 = 1.2°C Q = m Cp dt = 50.103 *4.18 x 1.2 9 = 251.3 c = 0.2513 KJ molyy 2n = 0.103 = 1.58xió 65.39 = = AH = - -159 kJ/md. -0.2513 7-58 x103 159 Answer: B 6 b) red light Note for this problem one 'n' value missed Cannot answer. You cut the problem so