REFERENCE

https://www.youtube.com/watch?v=KXG-ixd6nwQ

http://www.dynamicscience.com.au/tester/solutions1/chemistry/gas/fractionaldistofair.gif

https://en.wikipedia.org/wiki/Air_separation

https://www.google.com/search?q=fractional+distillation+of+air&client=firefox-b-d&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjW9IbLrOrgAhUh0uAKHboDDZIQ_AUIDigB&biw=1354&bih=647#imgrc=XWC_IAKT32o-uM

K.L.B Secondary Chemistry book 1 pgs 27

K.L.B Comprehensive Chemistry book 1 pgs 17-18