Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in grams) of the salt required…

Formula of $\mathrm{ppm}$ is as follow-

$\mathrm{ppm}=\frac{\mathrm{weight} \mathrm{of} \mathrm{solute}}{\mathrm{weight} \mathrm{of} \mathrm{solution}}\times {10}^6$

$10=\frac{Mass\hspace{0.17em}of\hspace{0.17em}Fe\left(ing\right)}{100\times 1000}\times {10}^6$
Or mass fe $=1g$
$FeS{O}_4.7H_{2}O\left(M=278\right)$
56g in 1 mole
$1g-\frac{1}{56}\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{e}$
$\frac{1}{56}\times 278g=4.96g$

PPM is a concentration term and its full form is "parts per million" and it also can be expressed as milligrams per liter (mg/L). This measurement is the mass of a chemical or contaminate per unit volume of water.