11) Calculate the wavenumber in cm^-1 of an infrared absorption peak at 785 mHz. A) 2.62times 10^-9cm^-1 B) 3.82times 10^8cm^-1 C) 2.36times 10^8cm^-1 D) 4.24times 10^-9cm^-1 B) 2.55times 10^-6cm^-1

To calculate the wavenumber in $cm^{-1}$ of an infrared absorption peak at 785 MHz, we can use the formula:<br /><br />Wavenumber = 1 / (wavelength in meters)<br /><br />First, we need to convert the frequency from MHz to Hz:<br /><br />785 MHz = 785 x 10^6 Hz<br /><br />Next, we can use the speed of light (c) to find the wavelength:<br /><br />c = 3 x 10^8 m/s<br /><br />Wavelength = c / frequency<br /><br />Wavelength = (3 x 10^8 m/s) / (785 x 10^6 Hz)<br /><br />Wavelength = 0.382 x 10^-6 m<br /><br />Now, we can calculate the wavenumber:<br /><br />Wavenumber = 1 / (wavelength in meters)<br /><br />Wavenumber = 1 / (0.382 x 10^-6 m)<br /><br />Wavenumber = 2.62 x 10^9 $cm^{-1}$<br /><br />Therefore, the correct answer is A) $2.62\times 10^{-9}cm^{-1}$.