Chemistry - Concentration Terms Question with Solution | TestHub

As 500 g of toothpaste$\equiv 0.2$g of${\mathrm{F}}^{-}$
So$10^6$g of toothpaste$\equiv \frac{\text{0}\text{.2}\text{g}\text{×}{\text{10}}^{\text{6}}\text{g}}{\text{500}\text{g}}{\text{F}}^{-}$
$=400\text{ g}{\text{F}}^{-}$
Hence, concentration in ppm is 400.