Question

The mass of CaO that shall be obtained by heating 20kg of 90% pure lime stone(CsCO3) is

Answer 1

EQUATION

caco3cao+o2
100kg      56kg  32kg

real mass of the equation respectively

but it is given 
20kg of 90% caco3

first step you should find the amount of caco3 given in sum
so,
90 is in persentage so to convert 
and and the mass 20 kg  is heated to obtain pure lime stone

to make it easy for you i will form like this

20kg limestone heated90%of pure lime stone

now calculation to find amount given in eqation

pure caco320*90/100

                       1800/100
                           
                         18kg

from equation,


          100g of caco3 gives cao is  56

          18g caco3 gives cao is         56*18/100
                                               
                                                        1008/100

                                                        10.08 kg

             hope its help full

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