Question

calculate how much lime will be obtained by heating 500g of lime stone of 50%purity? (ca=40,C= 12,O=16)​

Answer 1

We have to calculate the amount of line obtained by heating 500g of lime stone of 50% purity.

solution : chemical formula of lime stone is CaCO3 and lime is CaO

when lime stone is heated, carbon dioxide evolves and lime is formed.

i.e., CaCO3 => CaO + CO2

here you see 1 mole of lime stone forms 1 mole of lime. ....(1)

given mass of lime stone is 500 but purity of it is 50%

so mass pure lime stone = 50 % of 500 = 250 g

now no of moles of lime stone = 250g/100g/mol = 2.5 mol [ molecular mass of CaCO3 is 100g ]

from equation (1),

we can say that no of mole of lime will be formed = 2.5 mol

so mass of lime = 2.5 × molecular mass of Lime

= 2.5 mol × 56 g/mol

= 140 g

Therefore the amount of lime will be obtained is 140g.