Chemistry - Concentration Terms Question with Solution | TestHub

$10\text{ppm}$ means $10\text{parts}$ of solute in $10^6\text{parts}$ of solution. For dilute aqueous solutions with density approximately $1\text{g/mL}$, $1\text{ppm}$ is equivalent to $1\text{mg/L}$. Therefore, $10\text{ppm}$ of ${\text{CaCO}}_3$ corresponds to $10\text{mg/L}$. To convert milligrams to grams, we divide by $1000$: $10\text{mg/L}=10\times 10^{-3}\text{g/L}$. Therefore, option A is correct.