P/s : Bị trôi bài , mk không để ý !
Khí thoát ra là N2
\(\Rightarrow n_N=2n_{N2}=0,05\left(mol\right)\)
\(\Leftrightarrow m_N=0,7\left(g\right)\)
\(n_{CaCO3}=n_{CO2}=0,3\left(mol\right)=n_C\)
\(\Rightarrow m_{CO2}=13,2\left(g\right)\)
\(m_{binh.tang}=m_{CO2}+m_{H2O}\)
\(\Rightarrow m_{H2O}=6,3\left(g\right)\)
\(\Rightarrow n_H=2n_{H2O}=0,7\left(g\right)\)
\(m_C=3,6\left(g\right)\)
\(m_C+m_H+m_N< m_A\Rightarrow\) A có O.
\(\%m_C=\frac{3,6}{8,9}.100\%=40,45\%\)
\(\%m_H=\frac{0,7}{8,9}.100\%=7,87\%\)
\(\%m_O=100\%-\left(40,45+7,87\right)=43,81\%\)