Найти массовые доли элементов в веществах: no3, so3, h2so4

M(NO3) = 14+3*16 = 62
W(N) = 14/62 = 0.23 =23%
W(O) = 48/62 = 0.77 = 77%

M(SO3) = 32+3*16 = 80
W(S) = 32/80 = 0.4 = 40%
W(O) = 48/80 = 0.6 = 60%

M(H2SO4) = 2*1+32+4*16 = 98
W(H) = 2/98 = 0.02 = 2%
W(S) = 32/98 = 0.33 = 33%
W(O) = 64/98 = 0.65 = 65%