Question

What mass of calcium carbonate, CaCO3, must be decomposed to give 14g of calcium oxide, CaO?

Answer 1

Mass of CaCO₃ decomposed = 25 g

Step-by-step explanation:

Given data:

Mass of CaCO₃ decomposed = ?

Mass of CaO produced = 14 g

Solution:

Chemical equation:

CaCO₃ → CaO + CO₂

Number of moles of CaO:

Number of moles = mass/molar mass

Number of moles = 14 g/ 56 g/mol

Number of moles =0.25 mol

Now we will compare the moles of CaO with CaCO₃.

CaO : CaCO₃

1 : 1

0.25 : 0.25

Mass of CaCO₃:

Mass = number of moles × molar mass

Mass = 0.25 mol × 100 g/mol

Mass = 25 g