# Calculating IR Energy: 1.614 x 107 MHz

• stacker
In summary, the energy (in kJ/mol) of infrared radiation with a frequency of 1.614 x 10^7 MHz can be calculated using the equation E = hv, where h is Planck's constant and v is the frequency in Hz. After properly converting the units, the energy is found to be 6.44 kJ/mol. The mistake in the attempt at the solution was not properly converting the Si-Units and neglecting the aspect of moles.
stacker

## Homework Statement

What is the energy (in kJ/mol) of infrared radiation that has a frequency of 1.614 x 107 MHz?

E = nhv

## The Attempt at a Solution

3 x 6.63 x 10^-34 (J x s) multiplied by 1.614 x 10^7 (MHz) multiplied by (10^6 Hz/1 MHz) multiplied by (1 kJ/ 1000J) = 3.210246 x 10^-20, which is wrong.

Last edited:

E = hv
v=1.614x10^13 hz
h = 6.63x10^-34
E = 1.07x10^-20 J
E/1000 = kJ
E = 1.07x10^-23 kJ
per mole
1.07x10^-23 * (6.02 x 10^23 atoms/mol)
E = 6.44 kJ/mol

hope that is clear, any questions let me know :)

nickdk said:
E = hv
v=1.614x10^13 hz
h = 6.63x10^-34
E = 1.07x10^-20 J
E/1000 = kJ
E = 1.07x10^-23 kJ
per mole
1.07x10^-23 * (6.02 x 10^23 atoms/mol)
E = 6.44 kJ/mol

hope that is clear, any questions let me know :)

Yes that's the right answer! But I'm still having trouble understanding why, in terms of units, you can multiply the last step by (6.02 x 10^23 atoms/mol) and still get units of (kJ/mol). When did the unit of "atoms" appear?

Reflection: I made the mistake of not properly converting the Si-Units of "Mega-x" to "x" and neglected the aspect of moles.

## 1. What is "Calculating IR Energy: 1.614 x 107 MHz"?

"Calculating IR Energy: 1.614 x 107 MHz" refers to the process of determining the amount of infrared (IR) energy emitted by a source at a frequency of 1.614 x 107 megahertz (MHz).

## 2. Why is it important to calculate IR energy?

Calculating IR energy is important in understanding the amount of thermal radiation emitted by a source. It can help in various applications such as designing heating systems, studying climate change, and analyzing the energy efficiency of materials.

## 3. How is IR energy calculated?

IR energy is calculated using the formula E = hν, where E is the energy in joules (J), h is Planck's constant (6.626 x 10-34 J*s), and ν is the frequency in hertz (Hz). To convert from MHz to Hz, multiply the frequency by 1,000,000.

## 4. What factors can affect the amount of IR energy emitted?

The amount of IR energy emitted can be affected by the temperature and composition of the source, as well as external factors such as atmospheric conditions and the presence of other materials that may absorb or reflect the energy.

## 5. How is IR energy measured?

IR energy can be measured using instruments such as infrared cameras, spectrometers, and radiometers. These devices detect and measure the thermal radiation emitted by a source and convert it into a digital output or display.

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