Ce cantitate de O (oxigen) se afla in 490 g acid sufuric ?
M(masa atomica) acid sulfuric= 1*2+32+16*4=98 u.a.m(unitate atomica de masa)
98g acid sulfuric.............................64g H
490g acid sulfuric..........................x g H
x=[tex] \frac{490*64}{98} [/tex]=320 g O
