a) Ca + 2H2O → Ca(OH)2 + H2↑ (1)
CaO + H2O → Ca(OH)2 (2)
\(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
b) Theo Pt1: \(n_{Ca}=n_{H_2}=0,1\left(mol\right)\)
\(\Rightarrow m_{Ca}=0,1\times40=4\left(g\right)\)
\(\Rightarrow m_{CaO}=9,6-4=5,6\left(g\right)\)
\(\Rightarrow\%Ca=\dfrac{4}{9,6}\times100\%=41,67\%\)
\(\%CaO=\dfrac{5,6}{9,6}\times100\%=58,33\%\)
b) Theo PT1: \(n_{Ca\left(OH\right)_2}=n_{H_2}=0,1\left(mol\right)\)
\(n_{CaO}=\dfrac{5,6}{56}=0,1\left(mol\right)\)
Theo PT2: \(n_{Ca\left(OH\right)_2}=n_{CaO}=0,1\left(mol\right)\)
\(\Rightarrow\Sigma n_{Ca\left(OH\right)_2}=0,1+0,1=0,2\left(mol\right)\)
\(\Rightarrow m_{Ca\left(OH\right)_2}=0,2\times74=14,8\left(g\right)\)
