2000 cm 1 to m 1

Frequencies in IR are generally expressed in 1/ λ units; ie cm-1 since Infrared Spectroscopy E vib = (n+1/2)h(k/μ) 5/2 π where μ = m 1 m 2 /(m 1 +m 2 asymmetric NH2 stretches Wavenumbers, cm-1 500 1000 1500 2000 2500

since wavelengths are usually very small one often uses the nano meter (nm) m The frequency ν in the SI system is measured in reciprocal seconds 1 s − cm/m or 656 5 x 10 -7 cm or 1 523x10 4 cm -1 We can convert this to Hz by 

Video Tutorial 1: Elementary problem stretching line at 2000 cm -1 to the bond axis is given by where is the bond distance QUESTION 5 1 m 2 m I 2 I rμ

Convert lengths: Bingo caller's sheet 0 1 km 1 m 0 1 m 1 cm 100 m 100 cm 100 mm 10 mm 0 2 km 2 m 0 03 km 0 3 m 200 m 2000 mm 30 m 300 mm

2000 3600 3400 3200 3000 2800 2600 2400 wavenumber [cm ]-1 3 2 CH m kg s–2 Pressure, Stress Pascal Pa N m–2 = m–1 kg s–2 [1 bar = 105 Pa]

Thus, 1 cm = 1/100 m = 0 01 m There are 1000 mm in a metre, Thus, 1 mm = 1/ 1000 m = 0 001 m Measure of Example Basic Units Metres (m) Litres (L)

Copiable page 1 of 3 © Nuffield mm m or m mm A centimetre is one hundredth of a metre so cm m or m cm Think about F 2000 m = ______ km 3500 m 

Example 1: To convert 4200 cm to meters, write the units in order from largest to smallest km hm dam m dm cm mm Converting cm to m requires moving

(d) the total energy (in Joules) associated with 1 mole of photons (b) The wave number is 1/wavelength, but since the wavelength is in m, and the wave number should be in cm–1, we first change the wavelength into cm: = 5 89 x 10