\(C_xH_y+\left(x+\dfrac{y}{4}\right)O_2\underrightarrow{t^o}xCO_2+\dfrac{y}{2}H_2O\)
1 0,5
\(n_{CO_2}=\dfrac{22,4}{22,4}=1\left(mol\right)\)
\(n_{H_2O}=\dfrac{9}{18}=0,5\left(mol\right)\)
có: \(0,5x=0,5y\)
=> x : y = 1
có: \(M_A=\dfrac{3,9}{2,4:16}=26\)
có: \(\left(CH\right)_n=26\)
<=> 13n = 26
=> n = 2
=> CTPT của A: \(C_2H_2\)
CTCT: H - C \(\equiv\) C - H
b. Vt lại pthh: \(2C_2H_2+5O_2\underrightarrow{t^o}4CO_2+2H_2O\)
0,5 1 0,5
\(C_2H_2+Br_2\rightarrow C_2H_2Br_2\)
0,5 0,5
\(m_{dd.Br_2}=\dfrac{0,5.80.2.100}{16}=500\left(g\right)\)