Răspunsuri

2014-02-03T12:57:40+02:00
1) intr-un mol de substanta se gasesc 6,023*10^23 molecule; in 2 moli(28g/mol etena) ai 12,046*10^23 molecule.
2) daca in 58 g etena avem 8 g de hidrogen, intr-o 100 avem 14%
3) 2CH2= CH2 => 48 g C
4)2:4 = 1:2