My notes a sample that contains only manganese(ii) carbonate (mnco3, 114.95 g/mol) and iron(iii) carbonate (fe2(co3)3, 291.73 g/mol) weighs 0.1667 g. when it is dissolved in excess acid, 0.0665 g of carbon dioxide (co2, 44.01 g/mol) is liberated. what percentage, by mass, of manganese(ii) carbonate did the sample contain? assume all the carbon originally present is converted to carbon dioxide.