Solid fuel used in rockets is a mixture of $Fe_2O_3$ and $Al$ (in ratio $1:2$ by moles). The heat evolved $(kJ)$ per gram of the mixture is $............$. (Nearest integer)
Given: $\Delta H_{f}^{\ominus}(Al_2O_3) = -1700 \ kJ \ mol^{-1}$
$\Delta H_{f}^{\ominus}(Fe_2O_3) = -840 \ kJ \ mol^{-1}$
Molar mass of $Fe$,$Al$ and $O$ are $56$,$27$ and $16 \ g \ mol^{-1}$ respectively.

• A
  $3$
• B
  $2$
• C
  $5$
• D
  $4$