CH141f Study Guide - Midterm Guide: Magnesium Chloride, Electromagnetic Spectrum, Ultraviolet
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CH141 Fall 2016 Practice Exam 2
Name: _________________________________ Section A (Katz) / B (King)
Part I. Circle your answers for multiple choice questions
1. 550 nm electromagnetic radiation is in what region of the electromagnetic spectrum?
A) Ultraviolet
B) Visible
C) Infrared
D) Microwave
E) X-ray
2. Which of the following choices is false regarding the wave amplitude of electromagnetic radiation?
(Circle all that apply. There may be more than one answer)
A) For visible light, a larger wave amplitude correlates with a brighter light
B) A larger wave amplitude correlates with higher energy photons
C) A larger wave amplitude correlates with a larger number of photons
D) A larger wave amplitude correlates with a longer wavelength
E) A larger wave amplitude correlates with increased wave speed
3. Which of the following compounds will not undergo an acid-base (neutralization) reaction with
HClO4?
A) NaOH
B) Sr(OH)2
C) NH3
D) Na2CO3
E) H2SO4
4. If the ∆H° for the reaction, 2 Mg (s) + 2 Cl2 (g) → 2 MgCl2 (s), is -1283.6 kJ, what is the standard
enthalpy of formation of magnesium chloride?
A) 0 kJ/mol
B) -320.9 kJ/mol
C) -641.8 kJ/mol
D) 1283.6 kJ/mol
E) -1283.6 kJ/mol
5. Assign the proper oxidation state for the sulfur atom in each of the following species.
a) H2S _________
b) Na2SO4 _________
6. In one sentence, clearly explain why only some wavelengths of light are absorbed when a white light
source is directed through a sample of He gas.
CH141 Fall 2016 Practice Exam 2
Part II. Show All Your Work!
7. You place 2.80 g of phosphoric acid (H3PO4) into 150.0 mL of a 1.00 M sodium hydroxide solution. If
the total volume remains constant, identify the following:
a) The concentration of sodium ion at the completion of the reaction: _______________ M
b) The concentration of phosphate ion at the completion of the reaction: _____________ M
c) The concentration of hydroxide ion at the completion of the reaction: _____________ M
8. According to De Broglie’s theory, an electron moving at 12.5% the speed of light will display wave
behavior at what wavelength?
9. What is the energy of one mole of radio wave photons with a wavelength of 95.6 meters?