Đáp án:
2) CH2O2
3) CH4O
Giải thích các bước giải:
\(\begin{array}{l}
2)\\
2RCOOH + 2Na \to 2RCOONa + {H_2}\\
n{H_2} = \dfrac{{1,12}}{{22,4}} = 0,05\,mol \Rightarrow nA = 0,05 \times 2 = 0,1\,mol\\
MA = \dfrac{{4,6}}{{0,1}} = 46g/mol \Rightarrow MR = 1\,g/mol\\
\Rightarrow A:HCOOH(C{H_2}{O_2})\\
3)\\
2ROH + 2Na \to 2RONa + {H_2}\\
n{H_2} = \dfrac{{1,12}}{{22,4}} = 0,05\,mol \Rightarrow nA = 0,05 \times 2 = 0,1\,mol\\
\Rightarrow MA = \dfrac{{3,2}}{{0,1}} = 32g/mol \Rightarrow MR = 32 - 17 = 15\,g/mol\\
\Rightarrow R:C{H_3}\\
\Rightarrow A:C{H_3}OH(C{H_4}O)
\end{array}\)