X = вещество CaHb
m(x) = 15 / 2 = 7.5
w(C -> x) = 80%
w(H -> x) = 20%
Следовательно,
m(C -> x) = 7.5/100*80 = 6 г
m(H -> x) = 7,5/100*20 = 1,5 г
n(C -> x) = 6 / 16 = 0.375 моль
n(H -> x) = 1.5 / 1 = 1.5 моль
=> n(C -> x) = 0.375 * 8 = 3
=> n(H -> x) = 1.5 * 8 = 12
Следовательно, вещество x - C3H12