Concept explainers
(a)
Interpretation:
The wavelength of maximum emission of a tungsten filament bulb at 2870 K and 3750 K needs to be calculated.
Introduction:
The Wein’s displacement Law states that the maximum wavelength in micrometers for the radiations of the blackbody is represented as follows:
Here, T is defined as the temperature in Kelvin as it is absolute temperature.
Stefan’s law states that the total quantity of heat energy released per second per unit area by a perfect blackbody is directly proportional/related to the fourth power of the absolute temperature of its surface given by the equation:
Et = aT4
Where a has a value of
(b)
Interpretation:
The total energy output of the bulb in terms of W/m3 needs to be determined.
Concept introduction:
The Wein’s displacement Law states that the maximum wavelength in micrometers for the radiations of the blackbody is represented as follows:
Here, T is defined as the temperature in Kelvin as it is absolute temperature.
Stefan’s law states that the total quantity of heat energy released per second per unit area by a perfect black body is directly proportional/related to the fourth power of the absolute temperature of its surface given by the equation:
Et = aT4
Where a has a value of
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Chapter 7 Solutions
Principles of Instrumental Analysis
- Describe the differences and similarities between spontaneous and stimulated emission.arrow_forward(V) Consider solid and liquid samples of equal mass and heat capacity. If microwaves are fired at both samples, which one will increase in temperature faster? (VI) Using the Heisenberg uncertainty principle, calculate the frequency spread Av for a nanosec- ond (10-9 s) pulse from a CO2 laser, in which the nominal photon energy is hv = 0.112 eV.arrow_forward5. A 7.25x104 M solution of Potassium cyanide (KCN) has a transmittance of 45.2% when measured in a 2 cm cell at a wavelength of 525 nm. Calculate (a) the absorbance of this solution; (b) the molar absorptivity of KMNO4.arrow_forward
- (a) The surface of a metal is illuminated with light of wavelength 590nm. A PD of 0.15V is applied between the metal surface and the collecting electrodes in order to prevent the collection of electrons. Calculate:(i) The work function of the metal.(ii.) The work done against the most energetic photoelectrons.(iii.) The speed of the most energetic electrons. (b.) Light of varying frequencies is incident on the surface of three different metals x, y and z. The work functions wo of the metals are such that w0x < w0y < w0z. Sketch on the same axes graphs to show how the maximum kinetic energies of photoelectrons vary with frequency.arrow_forwardThe first excited state of Ca is reached by absorption of 422.7-nm light. (a) What is the energy difference (J) between the ground and excited states? (Hint: See Section 18-1.) (b) The degeneracies are g*/g0 3 for Ca. Find N*/N0 at 2 500 K. (c) By what percentage will the fraction in (b) be changed by a 15-K rise in temperature?arrow_forwardClearly describe the differences between fluorescence and phosphorescence. In your answer address the electronic states that are involved, the intensity, the wavelength and time scale of the specific emission process as well as what causes the difference in intensity, wavelength and time scale.arrow_forward
- A 7.21 x 10−5 M solution of potassium permanganate has a transmittance of 52.1% whenmeasured in a 3.81-cm cell at a wavelength of 550 nm. Calculate (a) the absorbance of thissolution and (b) the molar absorptivity of KMnO4arrow_forward(c) The kinetic energy, Kr, of electrons emitted from a metal surface after irradiation with UV light of wavelength λ is given by: hc K₁=-=- where h is Planck's constant (6.626 x 10-4 Js), c is the speed of light in a vacuum (2.99 x 108 m s¹), and is the work function of the metal surface. In a specific experiment, light with a wavelength of 266 nm was used to irradiate a cadmium (Cd) metal surface. (i) Calculate the photon energy of the light used in the experiment, in Joules. (II) The work function for cadmium is 4.08 eV. Calculate the kinetic energy of the emitted electrons. [Note: 1 eV = 1.60 x 10-19 J.)arrow_forwardDescribe how the attenuation of X-rays correlate with i) their photon energy, ii) the chemical make-up of the transmission material, and iii) the distance they have travelled through the material.arrow_forward
- (c) The kinetic energy, K, of electrons emitted from a metal surface after irradiation with UV light of wavelength is given by: Kg = hc $ where h is Planck's constant (6.626 x 10-4 Js), c is the speed of light in a vacuum (2.99 × 108 m s¹), and is the work function of the metal surface. In a specific experiment, light with a wavelength of 266 nm was used to irradiate a cadmium (Cd) metal surface. (1) Calculate the photon energy of the light used in the experiment, in Joules. (II) The work function for cadmium is 4.08 eV. Calculate the kinetic energy of the emitted electrons. [Note: 1 eV = 1.60 × 10-19 J.) (iii) The work function for scandium is 5.61 x 10-19 J. Calculate the wavelength of the lowest energy photon that would cause emission of electrons from a scandium surface. (iv) Irradiation of scandium with 335 nm light results in electrons emitted with a kinetic energy of 3.20 x 10-19 J. Calculate the de Broglie wavelength of the emitted electrons.arrow_forward(b) A system with chemical potential u = 12.5 meV contains identical particles each with integer spin and has a single quantum state at energy E, = 0 meV. The temperature of the system is fixed at 290 K. To three significant figures, what is the ratio Pg/P1, where P is the probability of finding a single particle in the state Eo, and P3 is the probability of finding 3 particles in this state? P3/P (Input your answer as a number.)arrow_forwardSound waves, like light waves, can interfere with each other, giving maximum and minimum levels of sound. Suppose a listener standing directly between two loudspeakers hears the same tone being emitted from both. This listener observes that when one of the speakers ismoved 0.16 m farther away, the perceived intensity of thetone decreases from a maximum to a minimum.(a) Calculate the wavelength of the sound.(b) Calculate its frequency, using 343 m s-1as the speedof sound.arrow_forward
- Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning