1. Stating the problem: Calculate masses or moles for given substances and confirm the code sequence I – J – G – D – A. 2. Mass of 0.042 mol Octane (C$_8$H$_{18}$): Molar mass of Octane $= 8\times12 + 18\times1 = 114$ g/mol Mass $= 0.042 \times 114 = 4.8$ g (I) 3. Mass of 4.02 mol Ba(NO$_2$)$_2$: Molar mass of Ba(NO$_2$)$_2 = 137.33 + 2\times(14.01 + 32.00) = 137.33 + 2\times46.01 = 229.35$ g/mol Mass $= 4.02 \times 229.35 = 921.95$ g (J) 4. Moles in 19.0 g Fluorine (F$_2$): Molar mass of F$_2 = 2\times19 = 38$ g/mol Moles $= \frac{19.0}{38} = 0.5$ mol (G) 5. Moles in 44.0 g NaH$_2$PO$_4$: Molar mass $= 23 + 2 + 31 + 4\times16 = 120$ g/mol Moles $= \frac{44.0}{120} = 0.37$ mol (D) 6. Moles in 1.04 g NaCl: Molar mass $= 23 + 35.5 = 58.5$ g/mol Moles $= \frac{1.04}{58.5} = 0.018$ mol \approx 0.02$ mol (A) 7. Conclusion: The code sequence with solutions is I (4.8 g), J (921.95 g), G (0.5 mol), D (0.37 mol), A (0.02 mol).