ms= 6g, c% = 40%
c% = mdx100/ms
=> md = msxc%/100 = 6x40/100 = 2,4 g formaldehida
CH2=O
=> 3 leg. sigma + 1 leg pi
M.CH2O = 30 g/mol
30g CH2O ....... 3x6,022x10la23 leg sigma ... 6,022x10la23 leg pi
2,4g CH2O ......................... x ................................... y
= 1,445x10la23 leg. sigma = 4,818x10la22 leg pi