Calcul de la dureté de l'eau avec la masse du précipité

[manishkob]

A 5mL hard water sample was reacted with sodium carbonate and when it became saturated, the formed precipitate had its mass be about 0.287 grams. Since hardness can be determined using calcium ions, how would I go about finding the hardness of the water sample in mg/L as CaCO3?showbox speed test