The molar mass of the water insoluble product formed from the fusion of chromite ore (FeCr2O4) with Na2CO3 in presence of O2 is g mol-1.
Answer
160
Solution
Fusion of chromite ore with sodium carbonate in free access of air:
4FeCr2O4 + 8Na2CO3 + 7O2 8Na2CrO4 + 2Fe2O3 + 8CO2
Na2CrO4 is water soluble (it is extracted with water); Fe2O3 is the water-insoluble product.
Molar mass of Fe2O3 = 2 56 + 3 16
= 112 + 48 = 160 g mol-1
Answer: 160