Question

What weight of calcium oxide will be formed on heating 19.3 g of calcium carbonate? 

(At. wt. : Ca = 40; C = 12; O = 16)

Answer 1

Given : 

Mass of CaCO₃ consumed in reaction = 19.3 g 

To find : 

Mass of CaO formed 

Calculation : 

Calcium carbonate decomposes according to the balanced equation,

So, 

100 g of CaCO₃ produce 56 g of CaO.

∴ Mass of CaO formed = 10.81 g

[Calculation using log table : 56 × 0.193 

= Antilog₁₀[log₁₀(56) + log₁₀(0.193)] 

= Antilog₁₀[1.7482 + \(\bar 1.2856\)] 

= Antilog₁₀[1.0338] 

= 10.81]