Question

Find the mass of calcium oxide produced from the thermal decomposition of 50 g of calcium carbonate.

[Ca=40, C=12, O=16]​

Answer 1

28 g

Step-by-step explanation:

The chemical equation of the reaction is given below:

CaCO₃ (s) ⇒ CaO (s) + O₂ (g)

From the chemical equation, 1 mole of CaCO₃ produces 1 mole of CaO.

So, we find the number of moles,n of CaCO₃ in 50 g from

n = m/M where n = number of moles of CaCO₃, m = mass of CaCO₃ and M = molar mass of CaCO₃ = 40 g/mol + 12 g/mol + 3 × 16 g/mol = 52 g/mol + 48 g/mol = 100 g/mol

So, n = m/M

= 50 g/100 g/mol

= 0.5 mol

Since From the chemical equation, 1 mole of CaCO₃ produces 1 mole of CaO, then 0.5 × 1 mole of CaCO₃ produces 0.5 × 1 mole of CaO, which is 0.5 mole of CaCO₃ produces 0.5 mole of CaO.

So, we have 0.5 mol of CaO.

We find the mass of CaO from

n =m'/M' where n = number of moles of CaO = 0.5, m' = mass of CaO and M' = molar mass of CaO = 40 g/mol + 16 g/mol = 56 g/mol

So, m' = nM'

= 0.5 mol × 56 g/mol

= 28 g