nFe2O3= 32/160=0.2mol
nCuO=28/80=0.35mol
mPbO=223*0.125=27.875g
số ptu Fe2O3=6*10^23*0.2=1.2*10^23(ptu)
=> số ntu Fe = .2*10^23 * 2= 2.4*10^23(ntu);
mFe = 0.2* 56* 2 = 22.4g
%Fe=(22.4/32)*100%=70%
sô ptu PbO = 6*10^23 * 0.125 = 7.5*10^22(ptu)
=>số ntu Pb=7.5*10^22(ntu)
mPb=0.125*207=25.875g
%Pb=(25.875/27.875)*100%=92.83%
số ptu CuO=6*10^23*0.35=2.1*10^23(ptu)
=>số ntu Cu = 2.1*10^23(ntu)
mCu= 0.35*64=22.4g
%Cu=(22.4/28)*100%=80%
\\tham khảo//
1) 32g Fe2O3
\(n_{Fe_2O_3}=\dfrac{32}{160}=0,2\left(mol\right)\)
Ta có: \(n_{Fe}=2n_{Fe_2O_3}=2\times0,2=0,4\left(mol\right)\)
\(\Rightarrow m_{Fe}=0,4\times56=22,4\left(g\right)\)
\(\%m_{Fe}=\dfrac{22,4}{32}\times100\%=70\%\)
Ta có: \(n_O=3n_{Fe_2O_3}=3\times0,2=0,6\left(mol\right)\)
\(\Rightarrow m_O=0,6\times16=9,6\left(g\right)\)
\(\%m_O=\dfrac{9,6}{32}\times100\%=30\%\)
2) 28g CuO
\(n_{CuO}=\dfrac{28}{80}=0,35\left(mol\right)\)
Ta có:\(n_{Cu}=n_O=n_{CuO}=0,35\left(mol\right)\)
\(\Rightarrow m_{Cu}=0,35\times64=22,4\left(g\right)\)
\(\%m_{Cu}=\dfrac{22,4}{28}\times100\%=80\%\)
\(m_O=0,35\times16=5,6\left(g\right)\)
\(\%m_O=\dfrac{5,6}{28}\times100\%=20\%\)
3) 45g Fe(OH)2
\(n_{Fe\left(OH\right)_2}=\dfrac{45}{90}=0,5\left(mol\right)\)
Ta có: \(n_{Fe}=n_{Fe\left(OH\right)_2}=0,5\left(mol\right)\)
\(\Rightarrow m_{Fe}=0,5\times56=28\left(g\right)\)
\(\%m_{Fe}=\dfrac{28}{45}\times100\%=62,22\%\)
Ta có: \(n_O=n_H=2n_{Fe\left(OH\right)_2}=2\times0,5=1\left(mol\right)\)
\(\Rightarrow m_O=1\times16=16\left(g\right)\)
\(\%m_O=\dfrac{16}{45}\times100\%=35,56\%\)
\(m_H=1\times1=1\left(g\right)\)
\(\%m_H=\dfrac{1}{45}\times100\%=2,22\%\)
4) 0,125 mol PbO
\(m_{PbO}=0,125\times223=27,875\left(g\right)\)
Ta có: \(n_{Pb}=n_O=n_{PbO}=0,125\left(mol\right)\)
\(\Rightarrow m_{Pb}=0,125\times207=25,875\left(g\right)\)
\(\%m_{Pb}=\dfrac{25,875}{27,875}\times100\%=92,83\%\)
\(m_O=0,125\times16=2\left(g\right)\)
\(\%m_O=\dfrac{2}{27,875}\times100\%=7,17\%\)
