Hi the question asks me to calculate the mass of calcium carbonate that must be decomposed to produce 14kg of calcium oxide.

Question

I think I've gone wrong somewhere, do you write 14000g or 14kg etc, could you help?

I did: Moles CaO=(Mass CaO/Mr CaO)
=1400/56
=25

CaO:CaCO3
1:1
25:25

Mass CaCo= Moles CaCO x Mr CaCO
=25 x 68
=1700
=1.7kg

Answer 1

CaCO3 ==> CaO + CO2
The process looks ok at first glance but the numbers are wrong. You should have used 14 kg = 14,000 g
Then 14,000/56 = 250
250 mols CaO (I would have used 56.1 for molar mass CaO)
Then 25o mols CaO = 250 mols CaCO3

Then mass CaCO3 = mols CaCO3 x molar mass CaCO3 = 250 x 100.(not 68)
The answer will be in units of grams. Convert to kg if that is needed.

Answer 2

Thank you so much!