Ответ:
дано
m(Al) =10.8 g
m(S) = 32 g
---------------
m(AL2S3)-?
2Al+3S-->Al2S3
M(Al) = 27 g/mol
n(Al) = m/M = 10.8 / 27 = 0.4 mol
M(S) = 32 g/mol
n(S) = m/M = 32 / 32 = 1 mol
n(AL) < n(S)
2n(Al) = n(Al2S3)
n(Al2S3) = 0.4 / 2 = 0.2 mol
M(Al2O3) = 102 g/mol
m(Al2O3) = n*M = 0.2 * 102 = 20.4 g
ответ 20.4g
Объяснение: