Solution:
Solution
MgCO3?→MgO+CO2?
The molar masses of MgCO3? and MgO are 24+12+48=84 g/mol and 24+16=40 g/mol respectively.
Thus, 8 g MgO will be obtained from (84 / 40)?×8=16.8 mg of MgCO3??.
The percentage purity of magnesium carbonate in the sample is 16.8 ?×100/ 20=80%
