Chemistry Question from JEE Main 2023 · 30 January, Shift 1

Some amount of dichloromethane ($CH_2Cl_2$) is added to $671.141 \, \text{mL}$ of chloroform ($CHCl_3$) to prepare a $2.6 \times 10^{-3} \, M$ solution of $CH_2Cl_2$ (DCM). The concentration of DCM is _____ ppm (by mass).

Given: Atomic mass $C = 12$, $H = 1$, $Cl = 35.5$, density of $CHCl_3 = 1.49 \, \text{g cm}^{-3}$.