nhh = 13.44/22.4 = 0.6 (mol)
nBr2 = 0.2 (mol)
C2H2 + 2Br2 => C2H2Br4
0.1______0.2
nCH4 = 0.6 - 0.1 = 0.5 (mol)
%CH4 = 0.5/0.6 * 100% = 83.33%
%C2H2 = 16.67%
13.44 (l) => 0.1 (mol) C2H2
6.72 (l) => x(mol) C2H2
=> x = 0.05
m tăng = mC2H2 = 0.05*26= 1.3 (g)