Răspuns:
a) 720g oxigen
b) 480g oxigen
c) 720g oxigen
d) 240g oxigen
Explicație:
a)
M(Al₂O₃) = 2 × A(Al) + 3 × A(O) = 2 × 27 + 3 × 16 = 102 g/mol
1 mol Al₂O₃..........48g O
15 mol Al₂O₃..........x g O
x = 15 × 48 = 720g O
b)
M(Ba(OH)₂) = A(Ba) + 2 × A(O) + 2 × A(H) = 137 + 2 × 16 + 2 × 1 = 171 g/mol
1 mol Ba(OH)₂..........32g O
15 mol Ba(OH)₂..........y g O
y = 15 × 32 = 480g O
c)
M(HNO₃) = A(H) + A(N) + 3 × A(O) = 1 + 14 + 3 × 16 = 63 g/mol
1 mol HNO₃..........48g O
15 mol HNO₃..........z g O
z = 15 × 48 = 720g O
d)
M(CaOCl₂) = A(Ca) + A(O) + 2 × A(Cl) = 40 + 16 + 2 × 35,5 = 127 g/mol
1 mol CaOCl₂..........16g O
15 mol CaOCl₂..........w g O
w = 15 × 16 = 240g O
-Mihai
