Масса воды450 мл=450г масса раствора 450+8=458 8/458 =0,017 или 1,7%
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
<span>А) в водной среде при нагревании:
</span><span>C6H5–CH3 + 2KMnO4 =
C6H5COOK + 2MnO2 + KOH + H2O
</span><span>Б) в кислой среде:
5C6H5–CH3 + 6KMnO4 +
9H2SO4 = 5C6H5COOH + 6MnSO4 +
3K2SO4 + 14H2O
</span>
стеариновая <span>C</span>18<span>H</span>36<span>O</span>2<span>, или CH</span>3<span>(CH</span>2<span>)</span>16<span>COOH. </span>
Ar(Cu)=64
Ar(O)=16
w=(n*Ar)/Mr
Mr(CuO)=64+16=80
w(Cu)=64/80=0,8=80%
w(O)=16/80=0,2=20%
Ответ: w(Cu)=80%, w(O)=20%