https://www.youtube.com/watch?v=fuk1zTdJifM
https://www.youtube.com/watch?v=__stMf3OLP4
https://www.youtube.com/watch?v=E2s8vScslR4
https://www.youtube.com/watch?v=DKOB0TTaFI8
http://che31.weebly.com/uploads/3/7/4/3/3743741/lect10-matbal_reactive_process.pdf
https://people.utm.my/hasrinah/files/2015/04/06-SKKK1113-201415_2-CHAP-4.4-4.6.pdf