Có \(\dfrac{m_C}{m_H}=\dfrac{12.n_C}{1.n_H}=\dfrac{3}{0,25}\)
=> \(\dfrac{n_C}{n_H}=\dfrac{1}{1}\)
=> CTPT: (CH)n
Mà M = 26g/mol
=> n = 2
=> CTPT: C2H2
Ta có: \(m_C:m_H=3:0,25\\ \Rightarrow\dfrac{m_C}{3}=\dfrac{m_H}{0,25}=\dfrac{m_C+m_H}{3+0,25}=\dfrac{m_Y}{3,25}=\dfrac{26}{3,25}=8\)
\(\dfrac{m_C}{3}=8\Rightarrow m_C=8.3=24\left(g\right)\Rightarrow n_C=\dfrac{24}{12}=2\left(mol\right)\)
\(\dfrac{m_H}{0,25}=8\Rightarrow m_H=8.0,25=2\left(g\right)\Rightarrow n_H=\dfrac{2}{1}=2\left(mol\right)\)
\(CTHH:C_2H_2\)