Mr(H2SO4) = 1*2 + 32 + 16*4 = 98
W(O) = Ar(O) * n / Mr(H2SO4) *100% = 16*4 / 98 *100% =65 %
Mr(HNO3) = 1 + 14 + 16*3 = 63
W(O)= Ar(O) * n / Mr(HNO3) *100% = 16*3 / 63 *100% = 76%
Mr(H3PO4) = 1*3 + 31 + 16*4 = 98
W(O)= Ar(O) * n / Mr(H3PO4) *100% = 16*4 / 98 *100% = 65%
Mr(NaOH) = 23+16+1 = 40
W(O) = Ar(O) * n / Mr(NaOH) *100% = 16*1/ 40 *100% = 40%
Ответ: NaOH