2MnCO3(s)+O2(g)2MnO2(s)+2CO2(g) In the second step, manganese(IV) oxide and aluminum react to form manganese and aluminum oxidide: 3MnO2(s)+4Al(s)3Mn(s)+2Al2O3(s) Suppose the yield of the first step is 92.% and the yield of the second step is 61.%. Calculate the mass of manganese(II) carbonate required to make 4.0kg of manganese. Be sure your answer has a unit symbol, if needed, and is rounded to the correct number of significant digits