1,
raport de combinare = raport atomic
avem 2 at H + 1 at C + 3 at O
=>
H : C : O = 2 : 1 : 3
2.
M.H2CO3 = 2x1+12+3x16 = 62 g/mol
62 g ....... 2x1g H ....... 12g C ........ 3x16g O
100% (g) ..... x% .............. y% .............. z%
= 3,23% = 19,35% = 77,42%
3.
1 mol H2CO3 .......... 3x16g O
10 moli ........................ m
= 480 g O
1 mol H2CO3 ........ 3x16g O ......... 6,023x10la23 molecule
m ..................... 6,023x10la22 molecule
= 4,8 g O