Question

A sample of calcium carbonate (CaCO3) is known to contain some impurities. It is found that Calcium makes up 11% of the entire mass of the sample. All of the Calcium comes from the CaCO3 compound. Find the mass percent of CaCO3 in the sample. Set up a ratio and solve.

Answer 1

28.05% is the mass percent of calcium carbonate in the sample.

Step-by-step explanation:

Suppose in 100 g of sample of impure calcium carbonate

Percentage of calcium in the sample = 11%

Mass of the calcium in the sample = 11% of 100 g =
`(11)/(100)* 100g=11 g`

Moles of calcium =
`(11 g)/(40 g/mol)=0.275 mol`

In 1 mole of calcium carbonate there are 1 mol of calcium .Then in 0.275 moles of calcium will be in :

`(1)/(1)* 0.275 mol=0.275 mol` calcium carbonate

Mass of 0.275 moles of calcium carbonate :

0.275 mol × 102 g/mol =28.05 g

Percentage of calcium carbonate in the sample:

`(28.05 g)/(100 g)* 100=28.05\%`

28.05% is the mass percent of calcium carbonate in the sample.