Gọi `n_{C_3H_6O}=x;n_{C_2H_6}=y` Bảo toàn `C`: `3x+2y={26,4}/44` Bảo toàn `H`: `3x+3y={13,5}/18` Giải hệ:`x=0,1;y=0,15` `m_1=58.0,1=5,8g;m_2=30.0,15=4,5g`
Tham khảo : $$n_{CO_2}=\dfrac{26,4}{44}=0,6(mol)$$ $$n_{H_2O}=\dfrac{13,5}{18}=0,75(mol)$$ `=>`$$n_H=0,75.2=1,5$$ `-` Đặt $$n_{C_3H_6O}=a(mol);n_{C_2H_6}=b(mol)$$ $$Cách \,\, 1:$$ `-` Bảo toàn nguyên tố $$C:$$$$3a+2b=0,6$$$$(1)$$ `-` Bảo toàn nguyên tố $$H:$$$$6a+6b=1,5$$$$(2)$$ `-` Từ $$(1),(2)$$ suy ra : $$a=0,1;b=0,15$$ `=>`$$m_1=0,1.58=5,8(g);m_2=0,15.30=4,5(g)$$ $$Cách \,\, 2:$$ `-` Bảo toàn nguyên tố $$H:$$$$6a+6b=1,5$$ `=>`$$a+b=0,25$$ `@` Công thức đốt cháy. $$n_{CO_2}-n_{H_2O}=(0-1)b$$ `->`$$b=0,75-0,6=0,15(mol)$$ `=>`$$a=0,25-0,15=0,1(mol)$$ `=>`$$m_1=0,1.58=5,8(g);m_2=0,15.30=4,5(g)$$