Ответ:
дано
m(AL) = 25 g
----------------------
m(H2)-?
2Al+6HCL-->2AlCl3+3H2
M(Al) = 27 g/mol
n(Al) = m/M = 25 / 27 = 0.93 mol
2n(AL) = 3n(H2)
n(H2) = 3*0.93 / 2 = 1.395 mol
M(H2) = 2 g/mol
m(H2) = n*M = 1.395 * 2 = 2.79 g
ответ 2.79 г
Объяснение:
Mr(О3)16×3=48
Mr(H3PO4)=1×3+31+16×4=98
Mr(C12H22O11)=12×12+1×22+16×11=144+22+176=342
Mr(N2O5)=14×2+16×5=28+80=108