дано
n(Al) = 2.6 mol
n(S) = 3.4 mol
m(Al2S3)-?
n(Al) < n(S)
2Al+3S-->Al2S3
2n(AL) = n(Al2S3) = 2.6 mol
n(Al2S3) = 2.6 / 2 = 1.3 mol
M(Al2S3) = 150 g/mol
m(Al2S2) = n*M = 1.3 * 150 = 195 g
ответ 195 г
