Question

20g of a mixture containing MgCo3 and MgCl2 is heated with dil. HCl, the amount of Co2 evolved is 4g , then the percentage composition of a mixture is​

Answer 1

Answer:

Percentage of MgCO3 = 38.18%

Percentage of MgCl2 = 61.82%

Explanation:

Only MgCO3 will react in this case

MgCO3(s) + 2 HCl(aq) = MgCl2(aq) + H2O(l) + CO2(g)

Molar mass of MgCO3 = 84

Molar mass of CO2 = 44

44g of CO2 is produced from 84g MgCO3

What about 4g of CO2 = (4 x 84)/44

                                       = 7.63 g

The original mixture has 7.63 g of MgCO3

Percentage of MgCO3 = 7.63/20 x 100 = 38.18%

Percentage of MgCl2 = 61.82%

Answer 2

here's the answer and hope it helps you