\(n_{Cl_2}=\dfrac{4.48}{22.4}=0.2\left(mol\right)\)
\(n_{NaBr}=0.5\left(mol\right)\)
\(2NaBr+Cl_2\rightarrow2NaCl+Br_2\)
\(0.4..........0.2...........0.4........0.2\)
\(m_X=m_{NaBr\left(dư\right)}+m_{NaCl}=\left(0.5-0.4\right)\cdot103+0.4\cdot58.5=33.7\left(g\right)\)