Question

a sample that contains only FeCO₃ and cuco3 weighs 0.8278 g. when it is dissolved in excess acid, 0.3047 g of carbon dioxide is liberated. what percentage of feco3 did the sample contain? assume all the carbon originally present is converted to carbon dioxide

Answer 1

To find the percentage of FeCO3, the moles of CO2 produced are converted to moles of FeCO3 using the molar mass. These moles are then used to determine the mass of FeCO3, which is then divided by the initial sample mass to find the percentage.

Step-by-step explanation:

To determine the percentage of FeCO3 that the sample contained, we use the mass of carbon dioxide (CO2) released. Since all the carbon in the sample was converted to CO2, we can calculate the mass of FeCO3 in the original sample.

The molar mass of CO2 is 44.01 g/mol, and from the given data, 0.3047 g of CO2 is produced. First, we find the number of moles of CO2:

Moles of CO2 = mass of CO2 / molar mass of CO2
= 0.3047 g / 44.01 g/mol
= 0.00692 mol CO2

Since the mole ratio of FeCO3 to CO2 is 1:1, 0.00692 mol of FeCO3 would produce the same moles of CO2. Now, we will calculate the mass of FeCO3 in the sample:

Mass of FeCO3 = moles of FeCO3 * molar mass of FeCO3
= 0.00692 mol * 115.85 g/mol
= 0.8014 g

Finally, to find the percentage of FeCO3, divide the mass of FeCO3 by the total mass of the sample and multiply by 100:

Percentage of FeCO3 = (mass of FeCO3 / total mass of sample) * 100
= (0.8014 g / 0.8278 g) * 100
= 96.81%