e1pf09key - 1. If the average bond energy for the C-H bond...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1. If the average bond energy for the C-H bond in methane is 435 kJ/mol. What frequency of light is needed to break the bond? a. 6.67 e35 Hz b. 1.09 e15 Hz c. 6.57 e38 Hz d. 1.09 e12 Hz ((435000 J/mol)*(1 mol/6.022 e23 photons))/(6.626 e-34 J*) = 1.09 e15 Hz 2. Which of the following statements is incorrect? a. The wavelength of light emitted by black body radiators decreases as the temperature of the body increases. b. The kinetic energy of electrons ejected by photons increases as the frequency of the incident radiation increases. c. The wavelength of matter is inversely proportional to mass. d. Photons of any wavelength will eject electrons from metal surfaces. Explanation: There is a minimum energy and, therefore, a minimum wavelength, necessary to eject electrons from metal surfaces. This is called the photoelectric effect. 3. If an electron falls to the energy level n=1, and an emission spectrum was observed at 102.3 nm, what energy level did it fall from? n= a. 2 b. 3 c. 4 d. 5 c/ λ = v (3 e8 m/s)/102.3 e-9 m = 2.93 e15 Hz v = R (1/nl^2 - 1/nu^2) nu = (1/nl^2 - v/R)^(-1/2) nu = (1/1^2 - 2.93 e15 Hz/3.3 e15 Hz)^(-1/2) = 3 4. If a particle is in a one-dimensional box of length 200 cm and is in its fourth energy level, at which of the following positions is the particle least likely to be found? a. 100 cm b. 75 cm c. 125 cm d. 130 cm The fourth energy level will have nodes at 50, 100 and 150 cm. 5. If the uncertainty in the position of a particle is 2.4 cm, what is the minimum uncertainty in the particles momentum? a. 2.2 e-35 m/s b. 4.4 e-33 m/s c. 2.2 e-33 m/s d. 4.4 e-35 m/s Δ p Δ x > /2 Δ p > /(2*Δ x) Δ p > (1.05 e-34 Js)/(2*.024 m) = 2.2 e-33 m/s 6. What is the wavelength of a particle with a momentum of 745 kg*m/s? a. 9.47 e-36 m b. 8.89 e-37 m c. 1.41 e-37 m d. 2.82 e-36 m λ = h/(mv) = h/p = 6.626 e-34 Js/745 kg*m/s = 8.89 e-37 m 7. Consider the species below. All of them will have the same number of V(r) terms in their respective solutions to the Schrodinger equation except for one of them. Which is the odd one out?
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
a. Ar b. K + c. S 2- d. Sc + The number of V(r) terms in a given solution to the Schrodinger equation is determined by the number of electrons. All of the species listed have the same number of electrons except for Sc + . 8. Which of the following quantum number values could apply to the valence electrons of
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/04/2011 for the course CH 302 taught by Professor Holcombe during the Spring '07 term at University of Texas at Austin.

Page1 / 7

e1pf09key - 1. If the average bond energy for the C-H bond...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online