Question

Dolomite is a carbonate of magnesium and calcium. Analysis shows that 7.81 g of dolomite contains 1.70 grams of Ca. Fluorite is a mineral of calcium and fluorine. Analysis shows that a 2.76 g sample of fluorite contains 1.34 grams of fluorine. On the basis of the mass percentage of Ca, and neglecting all other factors, which is the richer source of calcium: dolomite, or fluorite? Justify your answer showing all necessary calculations.

Answer 1

Answer:

The richer source of calcium is fluorite.

Explanation:

Percentage of element in compound :

$=\frac{\text{mass of element}}{\text{Mass of compound}}\times 100$

1. Dolomite is a carbonate of magnesium and calcium:

Given mass of dolomite = 7.81 g

Mass of calcium present in given mass of dolomite = 1.70 g

Percentage of calcium in Dolomite:

$=\frac{1.70 g}{7.81 g}\times 100=21.77\%$

2. Fluorite is a mineral of calcium and fluorine:

Given mass of fluorite = 2.76 g

Mass of fluorine present in given mass of fluorite = 1.34 g

Percentage of fluorine in fluorite :

$=\frac{1.34 g}{2.76 g}\times 100=48.55\%$

Percentage of calcium in fluorite = 100% - 48.55 % = 51.45%

Percentage of calcium in fluorite > Percentage of calcium in Dolomite

51.455 > 21.77%

So, the richer source of calcium is fluorite.