А) Mr(SO3) = 32 + 16*3 = 80
W(S) = Ar(S) * n / Mr(SO3) *100% = 32 *1 / 80 *100% = 40%
W(O) = Ar(O) *n / Mr(SO3) *100% = 16*3 / 80 *100% = 60%
б) Mr(K2CO3) = 39 *2 + 12 + 16*3 = 138
W(K) = Ar(K) * n / Mr(K2CO3) *100% = 39*2 / 138 *100% =56,5%
W(C) = Ar(C) * n / Mr(K2CO3) *100% = 12 *1 / 138 *100% = 8,7%
W(O) = Ar(O) * n / Mr(K2CO3) *100% = 16*3 / 138 *100% = 34,8%